Herbicical 2-[(4-heterocyclic-phenoxymethyl)phenoxy]-alkanoates

ABSTRACT

Herbicidal compounds, compositions containing them, and a method for controlling weeds by application of the compositions are disclosed. The herbicidal compounds are 2-[(4-heterocyclic(phenoxymethyl)phenoxy]alkanoates of the formula ##STR1## in which A is a derivative of an alkanoate bonded to the phenoxy oxygen at the alpha carbon, and Q is 4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl, 3,4,5,6-tetrahydrophthalimid-1-yl, 1-(1-methylethyl)imidazolidin-2,4-dion-3-yl, 1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-on-1-yl, 3-chloro-4,5,6,7-tetrahydroindazol-2-yl, 4-methyl-1,2,4-triazine-3,5-dion-2-yl, 8-thia-1,6-diazabicyclo[4.3.0]nonane-7-on-9-ylimino, or 1-methyl-6-trifluoromethyl-2,4-pyrimidinedione-3-yl; X is hydrogen, fluorine, or chlorine; Y is hydrogen; W is oxygen or sulfur; Z is hydrogen, fluorine, chlorine, bromine, lower alkyl, or methoxy; Z&#39; is hydrogen, fluorine, or chlorine; and the group AO-- may be in the 2, 3, or 4-position of the phenyl ring.

This invention pertains to novel herbicidal2-[(4-heterocyclic-substituted-3-halophenoxymethyl)phenoxy]alkanoates,especially propionates and acetates, and their use for weed control inagriculture, horticulture, and other fields in which it is desired tocontrol unwanted plant growth, such as grassy or broadleaf plantspecies. In particular, it pertains to those compounds in which theheterocyclic moiety is selected from among4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl,3,4,5,6-tetrahydrophthalimid-1-yl,1-(1-methylethyl)imidazolidin-2,4-dion-3-yl,1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-on-1-yl,3-chloro-4,5,6,7-tetrahydroindazol-2-yl,4-methyl-1,2,4-triazine-3,5-dion-2-yl,8-thia-1,6-diazabicyclo[4.3.0]nonane-7-on-9-ylimino, and1-methyl-6-trifluoromethyl-2,4-pyrimidinedione-3-yl groups. Thesecompounds are both pre- and postemergence herbicides. The use of thisclass of compounds as herbicides has not previously been described.

U.S. Pat. No. 5,084,085 discloses compounds of the formula: ##STR2##wherein

R^(a) is preferably lower haloalkyl, and R^(b) is preferably loweralkyl;

R' and R² are broadly defined;

X and Y are independently halogen, alkyl, alkoxy, alkylthio, haloalkyl,nitro, cyano, sulfonylalkyl, or --SOCF₃ ;

M is CH or N; and

A is a derivative of an alkanoate bonded to the phenoxy oxygen at thealpha carbon.

U.S. Pat. No. 4,816,065 discloses compounds like those of U.S. Pat. No.5,084,085, except that the triazolinone ring has been replaced by a3,4,5,6-tetrahydrophthalimido moiety. Similarly, U.S. Pat. No. 4,885,025discloses compounds in which the triazolinone ring of U.S. Pat. No.5,084,085 has been replaced with a tetrazolinone moiety.

U.S. Pat. No. 3,984,434, Japanese patents 54-25018, 54-6534, and60-39668, and Japanese patent applications 49-000432 and 54-19965, allassigned to Mitsubishi Chemical Industries, Ltd., disclose compounds ofthe general formula: ##STR3## wherein

X is hydrogen, halogen, nitro, alkyl, or alkoxy,

Y is hydrogen, halogen, alkyl, and n and m are each 1 to 4.

It has now been found that2-[(4-heterocyclic-substituted-3-halophenoxymethyl)phenoxy]alkanoatesare unexpectedly active as both pre- and postemergence herbicides. Inparticular, as preemergence herbicides many of these compounds exhibittolerance of soybeans and, to a certain extent, of corn. Perhaps ofgreater interest is the postemergence activity, where no crop toleranceis exhibited, making them excellent candidates as total vegetationcontrol agents.

The novel2-[(4-heterocyclic-substituted-3-halophenoxymethyl)phenoxy]alkanoates ofthe present invention are described by the following generic structure:##STR4##

Q is selected from the following heterocycles: ##STR5##

W is oxygen or sulfur;

X is selected from hydrogen, fluorine, or chlorine;

Y is hydrogen, or

X and Y taken together may be --O--C(CH₃)₂ CH₂ -- to form a7-substituted-4-benzofuranyl moiety;

R' is hydrogen or methyl;

R" is --OR or amino, arylamino (e.g. phenylamino), alkylamino (e.g.lower alkylamino such as methylamino or dimethylamino), alkenylamino(e.g. lower alkenylamino such as diallylamino), alkoxyamino (e.g. loweralkoxyamino such as methoxyamino), cyano, or alkyl-, haloalkyl-, orarylsulfonylamino of the formula --N(lower alkyl)SO₂ R⁹, or --NHSO₂ R⁹ ;

R is hydrogen, M, alkyl (e.g., lower alkyl such as methyl or ethyl),cycloalkyl, lower alkenyl or lower alkynyl (such as allyl or propargyl),or --[CHR⁷ (CH₂)_(m) O]_(n) R⁸,

each of R¹ through R⁶ is lower alkyl or lower haloalkyl;

R⁷ is hydrogen or lower alkyl;

R⁸ is alkyl, preferably lower alkyl;

R⁹ is alkyl (e.g. lower alkyl such as methyl, ethyl or propyl),haloalkyl (e.g. halo lower alkyl such as trifluoromethyl), or aryl suchas phenyl or substituted phenyl, (e.g. lower alkoxy-substituted and/orhalo-substituted phenyl);

m is 0 to 2, preferably 0 to 1, and n is 1 to 6, preferably 1 to 3; and

M is a monovalent, salt-forming group such as sodium, potassium, orammonium;

Z is hydrogen, fluorine, chlorine, bromine, lower alkyl, phenyl, ormethoxy;

Z' is hydrogen, fluorine, or chlorine; or

Z and Z' taken together may be --(CH₂)₄ -- to form a tetrahydronaphthylmoiety; and the group A--O-- may be in the 2, 3, or 4-position of thephenyl ring.

Preferred compounds are those in which R" is --OR, X is fluorine orchlorine, and Z is chlorine or lower alkyl.

Particularly preferred are those compounds in which R is lower alkyl or--[CHR⁷ (CH₂)_(m) O]_(n) R⁸ ; R¹ is difluoromethyl; R² is methyl; R³ is1-methylethyl; R⁴ is 3-fluoropropyl; R⁵ is methyl; R⁶ is methyl; R⁷ is Hor CH₃ ; R' is methyl; Z is in the 4-position; Z' is hydrogen orchlorine in the 3-position; m is 0 or 1, and n is 1 to 3; and the groupAO-- is in the 2-position of the phenyl ring.

Many of the compounds of the invention were prepared by the followingreaction: ##STR6##

An appropriately substituted methyl 2-(chloromethylphenoxy)alkanoate andan appropriately substituted 4-heterocyclic-substituted phenol wereheated in N,N-dimethylformamide at 80° C. in the presence of at least amolar equivalent of potassium carbonate. Usually the reaction was runovernight. Preparation of the corresponding acid (R═H) was accomplishedby hydrolyzing the ester with aqueous sodium hydroxide and thenacidifying the product with hydrochloric acid. For those compounds inwhich R is 2-(2-methoxyethoxy)ethyl, transesterification of the methylester with 2-(2-methoxyethoxy)ethanol in the presence of titanium (IV)isopropoxide was utilized.

Intermediates were prepared according to the following schemata:##STR7##

Thus, a mixture of an appropriately substituted formyl-substitutedphenol and a methyl 2-bromoalkanoate was heated at 70° C. in 2-butanonein the presence of potassium carbonate. Usually the reaction was runovernight, producing the corresponding 2-(substitutedformylphenoxy)alkanoate (IV). This compound was then reduced with sodiummethoxide and sodium borohydride in methanol, yielding the corresponding2-(hydroxymethylphenoxy)alkanoate (V). Reaction of V with thionylchloride in methylene chloride in the presence of a catalytic amount ofpyridine produced the corresponding 2-(chloromethylphenoxy)alkanoate(II). ##STR8##

To prepare compounds of the invention in which Q is4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl, a3-halo-4-fluoronitrobenzene was reacted with hydrazine in isopropanol atreflux, preparing the corresponding 2-halo-4-nitrophenylhydrazine (VI).Reaction of VI with pyruvic acid in ethanol and water produced the2-halo-4-nitrophenylhydrazone of pyruvic acid (VII). Preparation of thetriazolinone ring was accomplished by heating VII withdiphenylphosphoryl azide and triethylamine in toluene at reflux,producing1-(2-halo-4-nitrophenyl)-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one(VIII). Chlorodifluoromethane was then reacted with VIII and potassiumcarbonate in 1-methyl-2-pyrrolidinone by heating the mixture at 120° C.,producing1-(2-halo-4-nitrophenyl)-4-difluoromethyl-3-methyl-1,2,4-triazol-5(1H)-one(IX). Hydrogenation of IX in ethanol using platinum oxide as catalystproduced1-(4-amino-2-halophenyl)-4,5-dihydro-4-difluoromethyl-3-methyl-1,2,4-triazol-5(1H)-one(X). Preparation of intermediate III (a) was completed by reaction of Xwith sodium nitrite in sulfuric acid and subsequently with copper (II)sulfate in the presence of iron (II) sulfate in a mixture of water andxylenes. ##STR9##

To prepare the tetrahydrophthalimide-substituted intermediate (III(b)),an appropriately substituted 4-aminophenol was refluxed withtetrahydrophthalic anhydride, producing the correspondingN-(4-hydroxy-substituted-phenyl)tetrahydrophthalimide. ##STR10##

An appropriately substituted 4-nitrophenol was heated with methyl iodidein the presence of potassium carbonate in 2-butanone to prepare thecorresponding substituted 4-nitroanisole (XI). Compound XI washydrogenated over platinum oxide, producing a substituted4-methoxyaniline (XII). The reaction of XII with trichloromethylchloroformate prepared the corresponding substituted 4-methoxyphenylisocyanate (XIII). Reaction of this isocyanate with the ethyl ester ofglycine hydrochloride and triethylamine in chloroform yieldedN-(4-methoxy-substituted-phenyl)-N'-ethoxycarbonylmethylurea (XIV).Sequentially, XIV was reacted with sodium hydride and then with2-iodopropane, yielding ultimately1-(1-methylethyl)-3-(4-methoxy-substituted-phenyl)imidazolidin-2,4-dione(XV). Cleavage of the methoxy group of XV with boron tribromide yieldedintermediate III (c). ##STR11##

An appropriately substituted phenyl isocyanate (XIII(b)) was prepared bythe first three steps of Schema D and then was reacted withtrimethylsilyl azide to prepare the correspondingly substitutedphenyl-substituted tetrazolinone (XVI). After this tetrazolinone wasalkylated in the 4-position with 1-bromo-3-fluoropropane to make the3-fluoropropyl-substituted compound (XVII), the 4-fluorobenzylprotecting group was removed with 49% hydrobromic acid in acetic acid,yielding the desired hydroxy-substituted intermediate (XVIII). ##STR12##

The diazonium salt of 2-fluoro-4-methoxyaniline was prepared usingsodium nitrite and hydrochloric acid and was then reduced in situ withtin(II) chloride to prepare the correspondingly substitutedphenylhydrazine (XIX). Reaction of this hydrazine with ethyl2-cyclohexanonecarboxylate and subsequent heating of the product in thepresence of acetic acid produced a mixture of2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydro-1H-indazol-3-one (XX)and the 2-fluoro-4-methoxyphenylhydrazone of 2-cyclohexanonecarboxylicacid. This mixture was heated in phosphorus oxychloride, yielding3-chloro-2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydroindazole (XXI),which was then cleaved with boron tribromide to the desired3-chloro-2-(2-fluoro-4-hydroxyphenyl)-4,5,6,7-tetrahydroindazole (XXII).##STR13##

Etherification of 3-fluoro-4-nitrophenol with isopropyl iodide in thepresence of potassium carbonate produced2-fluoro-4-isopropoxynitrobenzene (XI(b)), which was reduced to2-fluoro-4-isopropoxyaniline (XII(b)) with iron in aqueous acetic acid.Malonic acid was reacted with urethane (ethyl carbamate) in phosphorusoxychloride to produce malonyldiurethane (XXIII). The reaction of XII(b)and XXIII was effected by sodium nitrite and hydrochloric acid,producing 2-(4-isopropoxy-2-fluorophenyl)hydrazonomalonyldiurethane(XXIV), which was cyclized with sodium hydroxide to the corresponding2-(substituted phenyl)-1,2,4-triazine-3,5-dion-6-carboxylic acid (XXV).Decarboxylation of XXV with thioglycolic acid and heat yielded XXVIwhich was then methylated at the 4-position with sodium hydride andmethyl iodide producing the corresponding 2-(substitutedphenyl)-4-methyl-1,2,4-triazine-3,5-dione (XXVII). In the final step theisopropyl protecting group was cleaved from the molecule withconcentrated sulfuric acid, producing the desired hydroxy-substitutedintermediate (XXVIII). ##STR14##

Preparation of the mercapto analog of intermediate III(a) started withintermediate X, which was converted to the corresponding diazonium salt.This diazonium compound was immediately reacted with copper (II)chloride and sulfur dioxide in aqueous acetic acid, producing thecorresponding substituted phenylsulfonyl chloride (XXIX). Reduction ofthe sulfonyl chloride moiety to a thiol group was effected using tin(II) chloride in acetic acid, yielding, for example,4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorothiophenol(XXX), the desired intermediate. ##STR15##

Unlike the preparation of the other heterocyclic-substituted herbicidalcompounds of this invention, where the final step is the reaction of IIand III to form the herbicide, in the preparation of the compounds inwhich Q is 8-thia-1,6-diazabicyclo[4.3.0]nonane-7-on-9-ylimino II and IIare first reacted to form an intermediate prior to forming theheterocycle. Thus, II was reacted with 3-fluoro-4-nitrophenol inN,N-dimethylformamide in the presence of potassium carbonate, yielding a2-(4-nitrophenoxymethylphenoxy)alkanoate (XXXI). Reduction of XXXI withiron and water in acetic acid produced the corresponding amino compound(XXXII), which was then converted to the isothiocyanate (XXXIII) withthiophosgene and trimethylamine. Perhydropyridazine monohydroiodide andXXXIII were then reacted, forming a2-(4-perhydropyridazin-1-ylthiocarbonylaminophenoxymethylphenoxy]alkanoate(XXXIV). Cyclization of XXXIV using trichloromethyl chloroformate andtriethylamine yielded, for example, methyl2-[2-[4-(8-thia-1,6-diazabicyclo[4.3.0]nonane-7-on-9-ylimino)-3-fluorophenoxymethyl]-5-methylphenoxy]propionate(XXXV), the desired herbicidal compound.

Similarly, the compounds in which Q is1-methyl-6-trifluoromethyl-2,4-pyrimidinedione-3-yl may be prepared bythe method of Schema I through the preparation of XXXII. Then XXXII isconverted to the isocyanate with phosgene in place of thiophosgene, andthe isocyanate is reacted with ethyl 3-amino-4,4,4-trifluoro-2-butenoateto yield the desired herbicidal compound.

In this specification "lower alkyl" contains 1 to 6 carbons, preferably1 to 4, "lower alkenyl" or "lower alkynyl" contains 2 to 6 carbons,preferably 2 to 4, "cycloalkyl" contains 3 to 6 carbons, and "halogen"or "halo" means bromine, chlorine, or fluorine, preferably chlorine orfluorine.

The methods for preparing the novel herbicidal compounds of theinvention are exemplified below.

All NMR spectra are reported as proton assignments in ppm in CDCl₃.

EXAMPLE 1 METHYL2-[2-[4-(4-DIFLUOROMETHYL-4,5-DIHYDRO-3-METHYL-1,2,4-TRIAZOL-5(1H)-ON-1-YL)-3-FLUOROPHENOXYMETHYL]-5-METHYLPHENOXY]PROPIONATE(Compound 12)

Step A: 2-Fluoro-4-nitrophenylhydrazine

To a solution of 20.0 g (0.126 mole) of 3,4-difluoronitrobenzene in 50mL of isopropyl alcohol was slowly added a solution of 4.04 g (0.126mole) of hydrazine in 20 mL of isopropyl alcohol, causing the reactionmixture to become orange. Upon completion of addition, the reactionmixture was heated at reflux for 30 minutes. A yellow solid, m.p.137°-139° C., was filtered from the reaction mixture. The NMR spectrumof this solid was consistent with 2-fluoro-4-nitrophenylhydrazine. Thisproduct was used in Step B without being fully dried, assuming a 100%yield.

Step B: 2-Fluoro-4-nitrophenylhydrazone of pyruvic acid

A thick mixture of 21.6 g (0.126 mole) of wet2-fluoro-4-nitrophenylhydrazine (Step A) in 100 mL of ethanol and 11.27g (0.128 mole) of pyruvic acid in 20 mL of water were mixed. After thereaction mixture had stirred for 20 minutes, it was filtered to yield15.5 g of a yellow solid, m.p. 210° C. (decomposition). An NMR spectrumof the product was consistent with the structure of the2-fluoro-4-nitrophenylhydrazone of pyruvic acid. This reaction wasrepeated to obtain additional product.

Step C:1-(2-Fluoro-4-nitrophenyl)-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one

A mixture of 29.62 g (0.123 mole) of the 2-fluoro-4-nitrophenylhydrazoneof pyruvic acid, 12.45 g (0.123 mole) of triethylamine, and 33.85 g(0.123 mole) of diphenylphosphoryl azide in 200 mL of toluene was heatedslowly to reflux. Heating at reflux was continued for two hours duringwhich this yellow mixture became an orange solution. After cooling toroom temperature, the reaction mixture was extracted with a solution of17.0 g (0.425 mole) of sodium hydroxide in 200 mL of water. The aqueousextract was separated and was almost completely neutralized withconcentrated hydrochloric acid. Just before pH 7 was reached, dry icewas added to the solution, completing the neutralization and causing abrown solid to precipitate. Filtration of this mixture yielded 26.15 gof1-(2-fluoro-4-nitrophenyl)-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-oneas a brown solid, m.p. 211°-212° C. The NMR spectrum was consistent withthe proposed structure.

Step D:1-(2-Fluoro-4-nitrophenyl)-4-difluoromethyl-4,5-dihydro-1,2,4-triazol-5(1H)-one

A mixture of 5.0 g (0.025 mole) of1-(2-fluoro-4-nitrophenyl)-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)oneand 29.0 g (0.210 mole) of dry, ground potassium carbonate in 200 mL of1-methyl-2-pyrrolidinone was heated at 120° C. for 30 minutes.Chlorodifluoromethane was bubbled into the reaction mixture for fiveminutes. Thin layer chromatography of the reaction mixture revealed thatthe reaction had not gone to completion. Therefore,chlorodifluoromethane was bubbled into the reaction mixture for anadditional three minutes. The reaction mixture was poured over ice andthen was neutralized with concentrated hydrochloric acid. This mixturewas extracted twice with diethyl ether. The combined extracts werewashed with water, dried over anhydrous magnesium sulfate, and filtered.The filtrate was evaporated under reduced pressure, leaving a dark brownsolid residue. This solid was dissolved in 100 mL of acetic acid and 5mL of hydrobromic acid, and this solution was heated at reflux for onehour. This mixture was poured over ice and was then extracted with ethylacetate. This extract was washed twice with water, dried over anhydrousmagnesium sulfate, and filtered. The filtrate was evaporated underreduced pressure, leaving a black oil as a residue. This residue was puton a silica gel column and eluted with methylene chloride/ethyl acetate(97.5/2.5). After the product-containing fractions had been combined,the solvents were evaporated under reduced pressure, leaving 4.6 g of1-(2-fluoro-4-nitrophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-oneas a residue, m.p. 72°-77° C. The NMR spectrum was consistent with theproposed structure.

This reaction was repeated to obtain additional1-(2-fluoro-4-nitrophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-onefor the remainder of the synthesis.

Step E:1-(2-Fluoro-4-aminophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one

A mixture of 24.5 g (0.085 mole) of1-(2-fluoro-4-nitrophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-oneand 0.30 g of platinum oxide in 250 mL of absolute ethanol washydrogenated in a Parr hydrogenation apparatus. The calculated amount ofhydrogen required was taken up in 45 minutes. The reaction mixture wasfiltered through a Buchner funnel, and the filtrate was evaporated underreduced pressure, leaving a dark brown solid residue. This residue wasplaced on a silica gel column and eluted with methylene chloride/ethylacetate (75/25). After the product-containing fractions were combined,evaporation of the solvents under reduced pressure yielded 20.1 g of1-(2-fluoro-4-aminophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one.The NMR spectrum was consistent with the proposed structure.

Step F:1-(2-Fluoro-4-hydroxyphenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one

A solution of 20.0 g (0.0774 mole) of1-(2-fluoro-4-aminophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-onein 100 mL of concentrated sulfuric acid was cooled to 15°-20° C. Asolution of 5.3 g (0.0774 mole) of sodium nitrite in 20 mL of water wasadded slowly to the sulfuric acid solution while the temperature wasmaintained between 15° C. and 20° C. The dark orange solution wasstirred for an hour at this temperature. The solution was then addedrapidly to a solution of 250 g (1.00 mole) of copper (II) sulfatepentahydrate and 2.0 g (0.0072 mole) of iron (II) sulfate heptahydratein 250 mL of water and 250 mL of mixed xylenes. This two-phase solutionwas heated at reflux for one hour, after which it was cooled and thephases separated. The organic layer was dried over anhydrous magnesiumsulfate and filtered. The filtrate was evaporated under reducedpressure, leaving a brown oil. The aqueous layer was extracted withethyl acetate, and the extract was dried over anhydrous magnesiumsulfate and then filtered. The extract was combined with the brown oilfrom the organic phase, and the solvent was evaporated under reducedpressure, again leaving a brown oil. This brown oil was placed on asilica gel column and eluted with methylene chloride/ethyl acetate(90/10). The product-containing fractions were combined, and the solventwas evaporated under reduced pressure, leaving 12.17 g of1-(2-fluoro-4-hydroxyphenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one,m p. 112°-114° C. The NMR spectrum was consistent with the proposedstructure.

Step G: 4-Methylsalicylaldehyde

A 1M solution of ethylmagnesium bromide in tetrahydrofuran (100 ml) wascooled to 15° C., and a solution of 10.81 g (0.100 mole) of m-cresol wasadded during a 45 minute period while the temperature was held at 15° C.Upon completion of the addition, the mixture was stirred at roomtemperature for 30 minutes, and then a mixture of 7.5 g (0.25 mole) ofparaformaldehyde and 17.92 g (0.100 mole) of hexamethylphosphoramide in200 mL of toluene was added in one portion. The resulting solution washeated at 80° C. for approximately seventeen hours, after which thesolvent was evaporated under reduced pressure, leaving a yellow residue.This residue was dissolved in diethyl ether, and this solution wasextracted with 50 mL of hydrochloric acid and 100 mL of water. Theorganic phase was separated, washed with water, and dried over anhydrousmagnesium sulfate. After filtration the solution was evaporated underreduced pressure, leaving an orange solid as a residue. This solid wasplaced on a silica gel column and eluted with methylenechloride/petroleum ether (50/50). Evaporation of the solvents yielded6.30 g of 4-methylsalicylaldehyde as a yellow solid, m.p. 51°-53° C. TheNMR and IR spectra were consistent with the proposed structure.

Step H: Methyl 2-(formyl-5-methylphenoxy)propionate

A mixture of 6.0 g (0.0441 mole) of 4-methylsalicylaldehyde, 7.31 g(0.0529 mole) of potassium carbonate, and 8.62 g (0.0529 mole) of methyl2-bromopropionate in 50 mL of 2-butanone was heated at 70° C. forapproximately seventeen hours. The mixture was then filtered, and thefiltrate was evaporated under reduced pressure, leaving a light yellowoil as a residue. This oil was placed on a silica gel column and elutedfirst with diethyl ether/petroleum ether (25/75) and then with diethylether. After the product-containing fractions were combined and thesolvents evaporated under reduced pressure, 8.2 g of methyl2-(2-formyl-5-methylphenoxy)propionate was recovered as a white solid,m.p. 65°-68° C. The NMR and IR spectra were consistent with the proposedstructure.

Step I: Methyl 2-(2-hydroxymethyl-5-methylphenoxy)propionate

To a solution of 7.89 g (0.0355 mole) of methyl2-(2-formyl-5-methylphenoxy)propionate in 20 mL of methanol, cooled to5° C., was added a solution of 0.10 g (0.001s mole) of sodium methoxidein 20 mL of methanol. While the temperature was maintained between 0° C.and 5° C., 0.36 g (0.0094 mole) of sodium borohydride was added to thereaction during a period of about 10 minutes. The reaction mixture wasallowed to warm to ambient temperature, where it was stirred for twohours. At the end of this period, the reaction mixture was poured into75 mL of 0.25N hydrochloric acid. This mixture was extracted twice withmethylene chloride. The combined extracts were washed with a saturatedaqueous solution of sodium chloride, dried over anhydrous magnesiumsulfate, and filtered. The filtrate was evaporated under reducedpressure, leaving a colorless oil as a residue. This oil was placed on asilica gel column and eluted first with methylene chloride/ethyl acetate(95/5 ) and then with the same solvents (90/10). After theproduct-containing fractions were combined and the solvents evaporatedunder reduced pressure, 5.76 g of methyl2-(2-hydroxymethyl-5-methylphenoxy)propionate was isolated as acolorless oil. The NMR and IR spectra were consistent with the proposedstructure.

Step J: Methyl 2-(2-chloromethyl-5-methylphenoxy)propionate

A solution of 2.20 g (0.0098 mole) of methyl2-(2-hydroxymethyl-5-methylphenoxy)propionate in 10 mL of dry methylenechloride was added to a colorless solution of 1.28 g (0.0108 mole) ofthionyl chloride and 5 drops of pyridine in 10 mL of dry methylenechloride during a 10 minute period. This mixture was heated at refluxfor one hour and then poured into 50 mL of water. The phases wereseparated, and the aqueous phase was extracted three times withmethylene chloride. These extracts were combined with the organic phase,which was then washed three times with a saturated aqueous solution ofsodium bicarbonate and once with a saturated aqueous solution of sodiumchloride. The organic phase was then dried over anhydrous magnesiumsulfate, filtered, and the filtrate was evaporated under reducedpressure, leaving a yellow oil as a residue. This oil was placed on asilica gel column and eluted with methylene chloride. After theproduct-containing fractions were combined and the solvent evaporatedunder reduced pressure, 2.06 g of methyl2-(2-chloromethyl-5-methylphenoxy)propionate was recovered as acolorless oil. The NMR spectrum was consistent with the proposedstructure.

Step K: Methyl2-[2-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]-5-methylphenoxy]propionate

A mixture of 0.50 g (0.0019 mole) of1-(2-fluoro-4-hydroxyphenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one,0.39 g (0.0028 mole) of anhydrous potassium carbonate, and 0.92 g(0.0038 mole) of methyl 2-(2-chloromethyl-5-methylphenoxy)propionate in20 mL of N,N-dimethylformamide was heated at 90° C. for approximately 17hours. At the end of this period the mixture was poured over ice, andthe resulting mixture was extracted with ethyl acetate. The extract waswashed with water, dried over anhydrous magnesium sulfate, and filtered.The filtrate was evaporated under reduced pressure, leaving an orangeoil as a residue. This oil was placed on a silica gel column and elutedfirst with methylene chloride and then with methylene chloride/ethylacetate (97.5/2.5). After the product-containing fractions were combinedand the solvents evaporated under reduced pressure, 0.82 g of2-[2-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]-5-methylphenoxy]propionatewas recovered as a yellow oil. The NMR and IR spectra were consistentwith the proposed structure. NMR: 1.60 (d, 3H, J_(HH) =8.0 Hz); 2.30 (s,3H); 2.44 (s, 3H); 3.76 (s, 3H); 4.84 (q, 1H, J_(HH) =8.0 Hz); 5.16 (dd,2H, J_(HH) =10.0 Hz); 6.56 (s, 1H); 6.78-7.32 (m, 6H).

EXAMPLE 2 METHYL2-[2-[3-FLUORO-4-(3,4,5,6-TETRAHYDRO-1-PHTHALIMIDYL)PHENOXYMETHYL]-5-CHLOROPHENOXY]PROPIONATE(Compound 27)

Step A: Synthesis of 4-amino-3-fluorophenol

To a mixture of 10.0 g (0.0640 mole) of 3-fluoro-4-nitrophenol in 100 mLof acetic acid and 10 mL of water heated to 50° C. was added 10.0 g(0.179 mole) of iron powder in small portions during a 35 minute period.The stirred reaction mixture was heated at 50° C. for an additionalthree hours, after which it was cooled and filtered. The filtrate wasused in Step B without further purification.

Step B: N-(2-fluoro-4-hydroxyphenyl)-3,4,5,6-tetrahydrophthalimide

The filtrate from Step A was mixed with 9.74 g (0.0640 mole) of3,4,5,6-tetrahydrophthalic anhydride, and the mixture was heated atreflux for approximately 64 hours. At the end of this period, the darkbrown solution was poured over ice and extracted in succession withethyl acetate and diethyl ether. The extracts were combined, washed withwater, dried over anhydrous magnesium sulfate, and filtered. Thesolvents were evaporated under reduced pressure from the filtrate,leaving a dark brown oil as residue. This was placed on a silica gelcolumn and eluted with methylene chloride/ethyl acetate (95/5). Afterthe product-containing fractions were combined and the solventsevaporated under reduced pressure, 14.71 g ofN-(2-fluoro-4-hydroxyphenyl)-3,4,5,6-tetrahydrophthalimide was recoveredas an orange solid, m.p. 132°-136° C. The NMR spectrum was consistentwith the proposed structure.

Step C: 4-Chlorosalicylaldehyde

A 2M solution of ethylmagnesium bromide in tetrahydrofuran (50 ml, 0.10mole) was placed in a flask, and a solution of 12.85 g (0.10 mole) of3-chlorophenol in 50 mL of diethyl ether was added slowly with stirring.The addition required two hours, after which the solvents were removedby evaporation under reduced pressure. Toluene (200 ml), 7.50 g (0.25mole) of paraformaldehyde, and 17.92 g (0.10 mole) ofhexamethylphosphoramide were added to the residue, and this mixture washeated at 80° C. for approximately 16 hours. The solvent was evaporatedunder reduced pressure, leaving a residue. This residue was washedsuccessively with 50 mL of hydrochloric acid and 300 mL of water. Vacuumdistillation of the washed residue yielded 11.50 g of4-chlorosalicylaldehyde, b.p. 112° C. at 9 mm of Hg. This reaction wasrepeated several times.

Step D: Methyl 2-(5-chloro-2-formylphenoxy)propionate

A mixture of 22.0 g (0.141 mole) of 4-chlorosalicylaldehyde, 30 g (0.22mole) of anhydrous potassium carbonate, and 30.0 g (0.184 mole) ofmethyl 2-bromopropionate in 120 mL of N,N-dimethylformamide was heatedat 80° C. for approximately 17 hours. At the end of that period, thereaction mixture was poured over ice and extracted successively withdiethyl ether and ethyl acetate. The combined extracts were washed withwater, dried over anhydrous magnesium sulfate, and filtered. Thesolvents were then evaporated under reduced pressure, leaving a residueweighing 20 g. This residue was purified by placing it on a silica gelcolumn and eluting with diethyl ether/petroleum ether (25/75). After theproduct-containing fractions were combined and the solvents evaporatedunder reduced pressure, 6.23 g of methyl2-(5-chloro-2-formylphenoxy)propionate was isolated as a yellow liquid.Similarly, other fractions were combined and evaporated, yielding 1.69 gof methyl 2-(3-chloro-2-formylphenoxy)propionate as a yellow liquid. TheNMR spectra of both compounds were consistent with proposed structure ofeach. This reaction was repeated several times.

Step E: Methyl 2-(5-chloro-2-hydroxymethylphenoxy)propionate

To a solution of 0.10 g (0.018 mole) of sodium methoxide in 20 mL ofmethanol that had been cooled to 5° C. was added a solution of 8.0 g ofmethyl 2-(5-chloro-2-formylphenoxy)propionate in 20 mL of methanol.While the temperature was maintained between 0° C. and 5° C., to thismixture was added 0.50 g (0.013 mole) of sodium borohydride. Thisaddition required 10 minutes, during which gas was evolved. The yellowsolution was allowed to warm up to room temperature, where it wasstirred for four hours. At the end of this period the reaction mixturewas poured into 100 mL of 0.25N hydrochloric acid. This mixture wasextracted with methylene chloride. The extract was washed with asaturated aqueous solution of sodium chloride, dried over anhydrousmagnesium sulfate, and filtered. The filtrate was evaporated underreduced pressure, leaving a yellow oil as a residue. This oil was placedon a silica gel column and eluted with methylene chloride/ethyl acetate(95/5 ). After the product-containing fractions were combined and thesolvents evaporated under reduced pressure, 4.42 g of methyl2-(5-chloro-2-hydroxymethylphenoxy)propionate was isolated as an orangeoil, which subsequently solidified, m.p. 51°-52° C.

Step F: Methyl 2-(2-chloromethyl-5-chlorophenoxy)propionate

By the method of Example 1, Step J, 1.0 g (0.0038 mole) of methyl2-(5-chloro-2-hydroxymethylphenoxy)propionate and 0.5 g (0.0042 mole) ofthionyl chloride were reacted in 20 mL of methylene chloride. Afterpurification, 0.88 g of methyl2-(2-chloromethyl-5-chlorophenoxy)propionate was isolated as a yellowliquid. The NMR spectrum was consistent with the proposed structure.

Step G: Methyl2-[2-[3-fluoro-4-(3,4,5,6-tetrahydro-1-phthalimidyl)phenoxymethyl]-5-chlorophenoxy]propionate

By the method of Example 1, Step K, 0.50 g (0.0019 mole) ofN-(2-fluoro-4-hydroxyphenyl)-3,4,5,6-tetrahydrophthalimide, 0.88 g(0.0034 mole) of methyl 2-(2-chloromethyl-5-chlorophenoxy)propionate,and 0.39 g (0.0028 mole) of potassium carbonate were reacted in 20 mL of2-butanone. After purification, 0.58 g of methyl2-[2-[3-fluoro-4-(3,4,5,6-tetrahydro-1-phthalimidyl)phenoxymethyl]-5-chlorophenoxy]propionatewas isolated as a yellow solid, m.p. 110°-112° C. The NMR and IR spectrawere consistent with the proposed structure. NMR: 1.64 (d, 3H, J_(HH) =8Hz); 1.80 (bs, 4H); 2.40 (bs, 4H); 3,78 (s, 3H); 4.84 (q, 1H, J_(HH)=8.0 Hz); 5.14 (s, 2H); 6.78-7.38 (m, 6H).

EXAMPLE 3 METHYL 2-[2-[3-FLUORO-4-[1-(1-METHYLETHYL)-IMIDAZOLIDIN-2,4-DION-3-YL]PHENOXYMETHYL]-5-CHLOROPHENOXY]PROPIONATE(Compound 44)

Step A: 3-Fluoro-4-nitroanisole

A mixture 25.0 g (0.16 mole) of 3-fluoro-4-nitrophenol, 27.6 g (0.20mole) of potassium carbonate, and 28.4 g (0.20 mole) of methyl iodide in2-butanone was heated at 70° C. for approximately 17 hours. The reactionmixture was then poured over ice and extracted with diethyl ether. Theextract was washed with water, dried over anhydrous magnesium sulfate,and filtered. The filtrate was evaporated under reduced pressure,leaving 24.35 g of 3-fluoro-4-nitroanisole as a solid residue. The NMRspectrum was consistent with the proposed structure. This product wasused in Step B without further purification.

Step B: 2-Fluoro-4-methoxyaniline

All of the product from Step A was placed in a Parr hydrogenationapparatus, and 0.35 g of platinum oxide in 200 mL of ethanol was added.This mixture was reacted with hydrogen until the theoretical amount ofhydrogen was absorbed. The reaction was stopped, and the reactionmixture was filtered through Celite® filter aid. The solvent was thenevaporated under reduced pressure, leaving 18.5 g of2-fluoro-4-methoxyaniline as a solid residue.

Step C: 2-Fluoro-4-methoxyphenyl isocyanate

To a solution of 13.75 g (0.0967 mole) of 2-fluoro-4-methoxyaniline in120 mL of toluene was slowly added over a period of 30 minutes asolution of 19.13 g (0.0967 mole) of trichloromethyl chloroformate in 30mL of toluene. During the addition the temperature rose to 35° C. Thereaction mixture was stirred without external heating for 30 minutes andthen heated at reflux for approximately 17 hours. At the end of thistime all of the solvent was removed by distillation, leaving2-fluoro-4-methoxyphenyl isocyanate as a purple liquid, which was usedimmediately in Step D.

Step D: N-(2-Fluoro-4-methoxyphenyl)-N'-ethoxycarbonylmethylurea

A solution of 2-fluoro-4-methoxyphenyl isocyanate (assumed to weigh 16.2g (0.0967 mole) from Step C), 13.50 g (0.0967 mole) of glycine ethylester hydrochloride in 100 mL of chloroform was placed in a flask, and asolution of 9.28 g (0.0967 mole) of triethylamine in 25 mL of chloroformwas added during a 20 minute period. The temperature rose to 38° C.during the addition. Upon completion of addition, the reaction mixturewas stirred at ambient temperature for three hours and then poured intoa mixture of heptane and water. By filtration,N-2(2-fluoro-4-methoxyphenyl)-N'-ethoxycarbonylmethylurea was isolatedfrom this mixture as a purple solid, m.p. 158°-159° C. The organic phaseof the filtrate was separated, dried over anhydrous magnesium sulfate,and filtered. The solvent was evaporated from the filtrate under reducedpressure, leaving a purple solid as residue. This solid wasrecrystallized from ethyl acetate/petroleum ether. The recrystallizedsolid was placed on a silica gel column and eluted sequentially withmethylene chloride, methylene chloride/ethyl acetate (90/10), andfinally methylene chloride/ethyl acetate (75/25). After theproduct-containing fractions were combined and the solvents evaporatedunder reduced pressure, additionalN-(2-fluoro-4-methoxyphenyl)-N'-ethoxycarbonylmethylurea was isolated asa purple solid, m.p. 158°-159° C. The total yield ofN-(2-fluoro-4-methoxyphenyl-N'-ethoxycarbonylmethylurea weighed 17.33 g.The NMR spectra of these solids were consistent with the proposedstructure.

Step E:1-(1-Methylethyl)-3-(2-fluoro-4-methoxyphenyl)imidazolidin-2,4-dione

A solution of 17.02 g (0.0630 mole) ofN-(2-fluoro-4-methoxyphenyl-N'-ethoxycarbonylmethylurea in 50 mL ofN,N-dimethylformamide was added dropwise to a suspension of 2.65 g(0.0662 mole) of sodium hydride in 30 mL of N,N-dimethylformamide duringa 20 minute period. Gas evolution and a slight rise in temperatureoccurred during the addition. This mixture was stirred at roomtemperature for 45 minutes, by which time it had become a homogeneoussolution. To this solution was added dropwise, over a period of 15minutes, a solution of 21.42 g (0.126 mole) of 2-iodopropane in 10 mL ofN,N-dimethylformamide. The temperature rose to 38° C. during theaddition period. This reaction mixture was stirred for approximately 65hours, then poured over ice and extracted with diethyl ether. Theextract was washed twice with water, dried over anhydrous magnesiumsulfate, and filtered. The filtrate was evaporated under reducedpressure, leaving an orange oil as a residue. This oil was placed on asilica gel column and eluted sequentially with 97.5/2.5 and 95/5mixtures of methylene chloride and ethyl acetate. After theproduct-containing fractions were combined and the solvents evaporatedunder reduced pressure, 5.85 g of1-(1-methylethyl-3-(2-fluoro-4-methoxyphenyl)imidazolidin-2,4-dione wasisolated as an orange solid, m.p. 88°-90° C.

Step F:1-(1-methylethyl)-3-(2-fluoro-4-hydroxyphenyl)imidazolidin-2,4-dione

A 1M methylene chloride solution of boron tribromide (41.6 ml, 0.0416mole) was cooled to -20° C. While this temperature was maintained, asolution of 5.55 g (0.0208 mole) of1-(1-methylethyl)-3-(2-fluoro-4-methoxyphenyl)imidazolidin-2,4-dione in25 mL of methylene chloride was added to the reaction during an eightminute period. The reaction mixture was allowed to warm to roomtemperature, where it was stirred for approximately 17 hours. At the endof this time the reaction was poured over ice, and the resultingtwo-phase mixture was filtered. The organic phase was separated, driedover anhydrous magnesium sulfate, and filtered. The filtrate wasevaporated under reduced pressure, leaving a black solid as a residue.This solid was recrystallized from ethyl acetate/petroleum ether, toyield 3.25 g of1-(1-methylethyl)-3-(2-fluoro-4-hydroxyphenyl)imidazolidin-2,4-dione asa tan solid, m.p. 190°-192° C. The NMR and IR spectra were consistentwith the proposed structure.

Step G: Methyl2-[2-[3-fluoro-4-[1-(1-methylethyl)imidazolidin-2,4-dion-3-yl]phenoxymethyl]-5-chlorophenoxy]propionate

By the method of Example 1, Step K, 0.60 g (0.0024 mole) of1-(1-methylethyl)-3-(2-fluoro-4-hydroxyphenyl)imidazolidin-2,4-dione,1.24 g (0.0048 mole) of methyl2-(2-chloromethyl-5-chlorophenoxy)propionate (Example 2, Step F), and0.5 g (0.0036 mole) of potassium carbonate were reacted in 25 mL of2-butanone. After purification, 1.04 g of methyl2-[2-[3-fluoro-4[1-(1-methylethyl)imidazolidin-2,4-dion-3-yl]phenoxymethyl]-5-chlorophenoxy]propionatewas isolated as a yellow oil. The NMR and IR spectra were consistentwith the proposed structure. NMR: 1.24 (d, 6H, J_(HH) =8 Hz); 1.64 (d,3H, J_(HH) =8 Hz); 3.68 (s, 3H); 3.96 (s, 1H); 4.44 (septet, 1H, J_(HH)=8.0 Hz); 5.04 (q, 1H, J_(HH) =8.0 Hz); 5.24 (s, 2 H); 6.80-7.34 (m,5H).

EXAMPLE 4 METHYL2-[2-[4-[1,4-DIHYDRO-4-(3-FLUOROPROPYL)-5H-TETRAZOL-5-ON-1-YL]-3-FLUOROPHENOXYMETHYL]-5-METHYLPHENOXY]PROPIONATE(Compound 64)

Step A: 4-Fluorophenylmethyl 3-fluoro-4-nitrophenyl ether

A stirred mixture of 10.0 g (0.063 mole) of 3-fluoro-4-nitrophenol, 17.0g (0.090 mole) of 4-fluorophenylmethyl chloride, and 12.42 g (0.090mole) of anhydrous potassium carbonate in 80 mL of methyl ethyl ketonewas heated at 70° C. for approximately 17 hours. The reaction mixturewas then cooled and filtered and the filtrate evaporated under reducedpressure, leaving 13.10 g of 4-fluorophenylmethyl 3-fluoro-4-nitrophenylether as a solid; m.p. 90°-91° C.

Step B: 4-Fluorophenylmethyl 4-amino-3-fluorophenyl ether

A solution of 11.0 g (0.041 mole) of 4-fluorophenylmethyl3-fluoro-4-nitrophenyl ether in 100 mL of glacial acetic acid and 10 mLof water was heated to 50° C. To this hot solution was added 1.0 g (0.18mole) of powdered iron. The reaction mixture was allowed to cool toambient temperature, where it stirred for an additional hour. Thereaction mixture was filtered through a bed of Celite® filter aid, andthe Celite bed was washed in succession with ethyl acetate and 200 mL ofwater. The washes and the filtrate were combined, and the organic phasewas separated. The organic phase was dried with anhydrous magnesiumsulfate, filtered, and the solvent was evaporated under reducedpressure, leaving a dark oil as a residue. This oil was placed on asilica gel column and eluted with methylene chloride. Theproduct-containing fractions were combined and the solvent evaporatedunder reduced pressure, leaving 6.8 g of 4-fluorophenylmethyl4-amino-3-fluorophenyl ether as a solid, m.p. 42°-43° C.

Step C: 4-(4-Fluorophenylmethoxy)-2-fluorophenyl isocyanate

To a solution of 6.50 g (0.0276 mole) of 4-fluorophenylmethyl4-amino-3-fluorophenyl ether in toluene, stirring at room temperature,was slowly added 3.95 g (0.020 mole) of trichloromethyl chloroformate.During the addition a thick precipitate formed. Upon completion ofaddition, the reaction mixture was stirred for one hour at roomtemperature and then at reflux for approximately seventeen hours. Thetoluene was removed by distillation, leaving 7.10 g of 4-(4-fluorophenylmethoxy)-2-fluorophenyl isocyanate.

Step D:1-[4-(4-Fluorophenylmethoxy)-2-fluorophenyl]-1,4-dihydro-5H-tetrazol-5-one

A mixture of 7.10 g (0.027 mole) of4-(4-fluorophenylmethoxy)-2-fluorophenyl isocyanate and 7.0 g (0.060mole) of trimethylsilyl azide was heated at reflux for approximatelyseventeen hours. The solution was then allowed to cool to roomtemperature before being poured over ice. A solid formed and wasrecovered by filtration. The solid was dried, leaving 8.08 g of1-[4-(4-fluorophenylmethoxy)-2-fluorophenyl]-1,4-dihydro-5H-tetrazol-5-one,m.p. 171°-172° C.

Step E:1-[4-(4-Fluorophenylmethoxy)-2-fluorophenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one

A mixture of 7.0 g (0.023 mole) of1-[4-(4-fluorophenylmethoxy)-2-fluorophenyl]-1,4-dihydro-5H-tetrazol-5-one,4.23 g (0.030 mole) of 1-bromo-3-fluoropropane, and 4.14 g (0.030 mole)of anhydrous potassium carbonate in 60 mL of N,N-dimethylformamide washeated at 70° C. for approximately seventeen hours. The mixture wasallowed to cool to room temperature before being poured over ice. Thesolid that formed was removed by filtration and dried. This solid wasthen placed on a silica gel column and eluted with with methylenechloride. The product-containing fractions were combined and thesolvents evaporated under reduced pressure, leaving 6.35 g of1-[4-(4-fluorophenylmethoxy)-2-fluorophenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one,m.p. 86°-88° C.

Step F:1-(2-Fluoro-4-hydroxyphenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one-To a solution of 5.60 g (0.0153 mole) of1-[4-(4-fluorophenylmethoxy)-2-fluorophenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-onein 60 mL of glacial acetic acid was added 5 mL of 49% hydrobromic acid.This mixture was heated at reflux for 90 minutes, after which it wascooled to room temperature. The reaction mixture was then poured overice, and the resulting aqueous solution was extracted with diethylether. The combined extract was dried over magnesium sulfate, filtered,and the solvent was evaporated under reduced pressure, leaving 4.35 g of1-(2-fluoro-4-hydroxyphenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-oneas a residue.

Step G: Methyl2-[2-[4-[1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-on-1-yl]-3-fluorophenoxymethyl]-5-methylphenoxy]propionate

By the method Example 1, Step K, 0.85 g (0.0033 mole) of1-(2-fluoro-4-hydroxyphenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-oneand 1.21 g (0.0050 mole) of methyl2-(2-chloromethyl-5-methylphenoxy)propionate (Example 1, Step J) werereacted in the presence of 0.70 g (0.0050 mole) of anhydrous potassiumcarbonate in 60 mL of N,N-dimethylformamide, yielding 0.42 g of methyl2-[2-[4-[1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-on-1-yl]-3-fluorophenoxymethyl]-5-methylphenoxy]propionateas an oil. The NMR spectrum was consistent with the proposed structure.NMR: 1.64 (d, 3H, J_(HH) =8 Hz); 2.2-2.4 (m, 2H); 2,32 (s, 3H); 3.72 (s,3H); 4.18 (t, 2H, J_(HH) =8 Hz); 4.50-4.64 (dt, 2H, J_(HH) =8 Hz, J_(HF)=45 Hz); 4.84 (q, 1H, J_(HH) =8 Hz), 5.20 (q, 2H, J_(HH) =8 Hz);6.58-7.40 (m, 6H).

EXAMPLE 5 METHYL2-[2-[4-(3-CHLORO-4,5,6,7-TETRAHYDROINDAZOL-2-YL)-3-FLUOROPHENOXYMETHYL]-5-CHLOROPHENOXY]PROPIONATE(Compound 66)

Step A: 2-Fluoro-4-methoxyphenylhydrazine

With vigorous stirring, 9.15 g (0.065 mole) of 2-fluoro-4-methoxyaniline(Example 3, Step B) was added to 60 mL of concentrated hydrochloric acidthat had been cooled to -10° C. A solution of 4.83 g (0.070 mole) ofsodium nitrite in 30 mL of water was slowly added dropwise, while thetemperature was kept at or below -10° C. Upon completion of addition,the reaction mixture was stirred at -10° C. for one hour, after which33.85 (0.150 mole) of tin(II) chloride dihydrate in 50 mL ofconcentrated hydrochloric acid Was added slowly, dropwise, while thetemperature was kept below -5° C. After the reaction mixture had stirredfor one hour as it warmed to ambient temperature, the crude product wasfiltered from the mixture and dissolved in 250 mL of water. Thissolution was made basic with 4N sodium hydroxide and extracted withmethylene chloride. The combined extracts were dried over anhydroussodium sulfate and filtered. The filtrate was placed on a silica gelcolumn and eluted with methylene chloride to remove colored impuritiesand then with ethyl acetate to obtain the desired product. The solventwas evaporated under reduced pressure to yield 6.30 g of2-fluoro-4-methoxyphenylhydrazine. The NMR spectrum was consistent withthe proposed structure.

Step B: 2-(2-Fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydro-1H-indazol-3-one

To a solution of 6.28 g (0.040 mole) of2-fluoro-4-methoxyphenylhydrazine in 200 mL of toluene was added withstirring 6.82 g (0.040 mole) of ethyl 2-cyclohexanonecarboxylate. Thismixture was heated at reflux under a nitrogen atmosphere while water wasremoved with a Dean-Stark trap. When all water had been removed, thereaction mixture was cooled, and the solvent was evaporated underreduced pressure, leaving a residue which was then dissolved in aceticacid. This solution was heated at reflux for approximately sixteenhours, after which the solvent was evaporated under reduced pressure,leaving a residue. This residue was dissolved in toluene, which was alsoevaporated under reduced pressure. The residue was dissolved in ethylacetate and placed on a silica gel column and eluted with ethyl acetate.An attempt to crystallize the product by dissolving it in diethyl etherafter the ethyl acetate had been evaporated was unsuccessful. After thesolvent had been evaporated from this product, it was again heated atreflux in acetic acid for 24 hours and allowed to cool to roomtemperature, where the solution stirred for an additional 48 hours. Thesolvent was evaporated under reduced pressure, leaving a residueweighing 4.32 g. Two additional fractions weighing 0.80 g and 2.75 g hadbeen recovered by extracting the reaction mixture before the solvent wasevaporated. The NMR spectrum of the residue showed it to be a mixture of2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydro-1H-indazol-3-one and the2-fluoro-4-methoxyphenylhydrazone of 2-cyclohexanonecarboxylic acid.

Step C:3-Chloro-2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydro-1H-indazole

The 4.32 g residue from Step B was mixed at ambient temperature with5.37 g (0.035 mole) of phosphorus oxychloride until complete dissolutionoccurred. At this point the reaction mixture was heated at reflux undernitrogen for one hour. The phosphorus oxychloride was evaporated fromthe reaction mixture under reduced pressure, leaving a residue weighing1.50 g. This residue, together with a similar residue weighing 0.30 gfrom an earlier experiment, was then was placed on a silica gel columnand eluted with hexane/ethyl acetate (4:1). After the product-containingfractions were combined and the solvents evaporated under reducedpressure, 0.50 g of3-chloro-2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydroindazole wasisolated. The NMR was consistent with the proposed structure.

Step D: 3-Chloro-2-(2-fluoro-4-hydroxyphenyl)-4,5,6,7-tetrahydroindazole

A 1N solution of boron tribromide in methylene chloride (18.0 mL, 0.018mole) was diluted with 17 mL of methylene chloride and was then cooledto below -10° C. under a nitrogen atmosphere. A solution of3-chloro-2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydroindazole in 25mL of methylene chloride was added dropwise at a rate to maintain thetemperature below -10° C. Upon completion of addition, the reactionmixture was allowed to warm to ambient temperature at which it stirredfor sixteen hours. The mixture was then poured into ice-water, and theresulting mixture was stirred for 30 minutes. This mixture was filtered,and the filtrate was passed through a short column of silica gel. Theorganic phase was separated, dried with anhydrous sodium sulfate, andfiltered. The solvent was evaporated from the filtrate under reducedpressure, leaving 0.60 g of3-chloro-2-(2-fluoro-4-hydroxyphenyl)-4,5,6,7-tetrahydroindazole as anearly white solid, m.p. 214°-216° C. The NMR and IR spectra wereconsistent with the proposed structure.

Step E: Methyl2-[2-[4-(3-chloro-4,5,6,7-tetrahydroindazol-2-yl)-3-fluorophenoxymethyl]-5-chlorophenoxy]propionate

By the method of Example 1, Step K, 0.49 g (0.0016 mole) of3-chloro-2-(2-fluoro-4-hydroxyphenyl)-4,5,6,7-tetrahydroindazole and0.52 g (0.002 mole) of methyl2-(2-chloromethyl-5-chlorophenoxy)propionate (Example 2, Step F) werereacted in the presence of 0.41 g (0.003 mole) of anhydrous potassiumcarbonate in 30 mL of N,N-dimethylformamide, yielding 0.64 g of methyl2-[2-[4-(3-chloro-4,5,6,7-tetrahydroindazol-2-yl)-3-fluorophenoxymethyl]-5-chlorophenoxy]propionateas a syrup. The NMR and IR spectra were consistent with the proposedstructure. NMR: 1.64 (d, 3H, J_(HH) =8.0 Hz); 1.82 (m, 4H); 2.50 (t, 2H,J_(HH) =4.0 Hz); 2.68 (t, 2H, J_(HH) =4.0 Hz); 3.76 (s, 3H); 4.82 (q,1H, J_(HH) =8 Hz); 5.18 (s, 2H,); 6.78-7.40 (m, 6H).

EXAMPLE 6 METHYL2-[2-[4-(4-METHYL-1,2,4-TRIAZINE-3,5-DION-2-YL)-3-FLUOROPHENOXYMETHYL]-5-METHYLPHENOXY]PROPIONATE(Compound 70)

Step A: 4-Isopropoxy-2-fluoronitrobenzene

By the method of Example 3, Step A, 23.15 g (0.147 mole) of3-fluoro-4-nitrophenol and 29.92 g (0.175 mole) of 2-iodopropane werereacted in the presence of 20.73 g (0.150 mole) of anhydrous potassiumcarbonate in 450 mL of acetone, yielding 28.0 g of4-isopropoxy-2-fluoronitrobenzene as an oil. The NMR was consistent withthe proposed structure.

Step B: 4-Isopropoxy-2-fluoroaniline

A stirred flask containing 350 mL of acetic acid was heated to 80°-85°C. under a nitrogen atmosphere. To this flask was added 39.10 g (0.700mole) of powdered iron, and this mixture was stirred for one hour. Asolution of 4-isopropoxy-2-fluoronitrobenzene in 250 mL was added to themixture dropwise. Upon completion of addition, the reaction mixture washeated at 80°-85° C. for one hour. After being cooled below 40° C., themixture was filtered, and the solvent was evaporated under reducedpressure, leaving a residue. This residue was dissolved in a mixture ofwater and diethyl ether. The organic layer was separated and was washedin succession with saturated aqueous solutions of sodium bicarbonate andsodium chloride. It was then dried over anhydrous magnesium sulfate,filtered through a short column of silica gel, and the solvent wasevaporated under reduced pressure, leaving an impure residue whichcontained significant amounts of acetamide in addition to the desiredproduct. This residue was suspended in 500 mL of 2N hydrochloric acidfor one hour. The hydrochloric acid mixture was then extracted withdiethyl ether, and the two phases were separated. Aqueous sodiumhydroxide solution was added to the aqueous hydrochloride solution untilit was basic. This basic solution was extracted with diethyl ether, andthe extract was dried over anhydrous magnesium sulfate and filtered.After evaporation of the solvent under reduced pressure, the residue wasrecrystallized from diethyl ether/petroleum ether to yield 16.90 g of4-isopropoxy-2-fluoroaniline as an oil which darkened on standing. TheNMR spectrum was consistent with the proposed structure.

Step C: Malonyldiurethane

With a mortar and pestle 10.40 g (0.100 mole) of malonic acid and 18.00g (0.210 mole) of ethyl carbamate were ground to a fine powder. Thispowder was placed in a flask, and 16.0 mL (0.167 mole) of phosphorusoxychloride was added. This mixture was heated at 80° C. until theevolution of gas ceased. After this reaction mixture had cooled toambient temperature, 210 mL of water was added. When the stiff glassymixture became fluid, it was extracted with ethyl acetate. The combinedextracts were washed in succession with saturated aqueous solutions ofsodium bicarbonate and sodium chloride and were then dried overanhydrous magnesium sulfate and filtered. The solution was filteredthrough a short column of silica gel, which was eluted with ethylacetate. The solvent was then evaporated under reduced pressure, leavinga crystalline mass of malonyldiurethane weighing 10.62 g. The NMRspectrum was consistent with the proposed structure.

Step D: 2-(4-Isopropoxy-2-fluorophenyl)hydrazonomalonyldiurethane

A mixture of 5.92 g (0.035 mole) of 4-isopropoxy-2-fluoroaniline, 10.60g (0.043 mole) of malonyldiurethane, and 41.02 g (0.500 mole) of sodiumacetate was suspended in 1000 mL of water with vigorous stirring. Tothis suspension was added 25 mL of 12N hydrochloric acid. The reactionmixture was cooled to 10° C., and, while this temperature wasmaintained, a solution of 2.42 g (0.035 mole) of sodium nitrite in 25 mLof water was slowly added. The reaction mixture was allowed to warmslowly to room temperature where it was stirred under a nitrogenatmosphere for approximately 16 hours. During this period a yellow solidformed and precipitated out. The mixture was filtered, and the yellowsolid was washed in succession with water and diethyl ether. After beingdried, 9.20 g of2-(4-isopropoxy-2-fluorophenyl)hydrazonomalonyldiurethane was isolatedas a yellow solid. The NMR and IR spectra were consistent with theproposed structure.

Step E:2-(4-Isopropoxy-2-fluorophenyl)-1,2,4-triazine-3,5-dion-6-carboxylicacid

To a stirred solution of 8.94 g (0.021 mole) of2-(4-isopropoxy-2-fluorophenyl)hydrazonomalonyldiurethane in 125 mL ofethanol and 125 mL of tetrahydrofuran was added 75 mL (0.134 mole) of10% aqueous potassium hydroxide, initially forming a precipitate, whichsubsequently dissolved. After this mixture was stirred for 30 minutes atambient temperature, 30 mL of 11.7N hydrochloric acid was addedcarefully with stirring. The tetrahydrofuran was evaporated underreduced pressure, and the residue was then extracted with ethyl acetate.The combined extracts were treated with decolorizing charcoal, driedover anhydrous magnesium sulfate, and filtered through a short column ofsilica gel, which was eluted with ethyl acetate. The solvent wasevaporated from the filtrate, yielding 4.70 g of2-(4-isopropoxy-2-fluorophenyl)-1,2,4-triazine-3,5-dion-6-carboxylicacid as an amorphous foam. The NMR spectrum was consistent with theproposed structure.

Step F: 2-(4-Isopropoxy-2-fluorophenyl)-1,2,4-triazine-3,5-dione

A solution of 4.70 g 0.0152 mole) of2-(4-isopropoxy-2-fluorophenyl)-1,2,4-triazine-3,5-dion-6-carboxylicacid in 5 mL of mercaptoacetic acid was heated at 140°-145° C. for twohours under a nitrogen atmosphere. After this mixture had cooled, it waspoured into 250 mL of a saturated aqueous solution of sodium bicarbonatewith vigorous stirring. An equal volume of ethyl acetate was added tothis mixture, and the resulting layers were separated. The organic layerwas washed twice with 150 mL of a saturated aqueous solution of sodiumbicarbonate and once with 150 mL of a saturated aqueous solution ofsodium chloride. The organic solution was then dried over anhydrousmagnesium sulfate and filtered. The solvent was evaporated under reducedpressure, leaving a syrup which slowly crystallized to a yellow-orangesolid upon standing. This solid was recrystallized from ethylacetate/petroleum ether (1:1), yielding 0.60 g of2-(4-isopropoxy-2-fluorophenyl)-1,2,4-triazine-3,5-dione as a yellowsolid. The NMR was consistent with the proposed structure. This reactionwas repeated to obtain additional material for subsequent reactions.

Step G:2-(4-Isopropoxy-2-fluorophenyl)-4-methyl-1,2,4-triazine-3,5-dione

A solution of 3.25 g (0.0123 mole) of2-(4-isopropoxy-2-fluorophenyl)-1,2,4-triazine-3,5-dione in 30 mL ofN,N-dimethylformamide was added to a suspension of 0.50 g (0.0125 mole)of sodium hydride in 30 mL of N,N-dimethylformamide at ambienttemperature. When gas evolution had ceased, 3.55 g (0.025 mole) ofiodomethane was added in one portion. This mixture was stirred for onehour without heating and was then poured into 300 mL of dilutehydrochloric acid. The resulting mixture was extracted several timeswith diethyl ether, and the extracts were combined. The ether extractwas washed in succession with water and a saturated aqueous solution ofsodium chloride. It was then dried over anhydrous magnesium sulfate andfiltered through a short column of silica gel. The solvent wasevaporated under reduced pressure, leaving 2.80 g of2-(4-isopropoxy-2-fluorophenyl)-4-methyl-1,2,4-triazine-3,5-dione as asyrup. The NMR was consistent with the proposed structure.

Step H: 2-(4-Hydroxy-2-fluorophenyl)-4-methyl-1,2,4-triazine-3,5,-dione

Concentrated sulfuric acid (5 mL) that had been cooled to 0°-5° C. wasmixed with 2.80 g (0.010 mole) of2-(4-isopropoxy-2-fluorophenyl)-4-methyl-1,2,4-triazine-3,5-dione thathad been cooled to 0° C. The mixture was maintained at 0° C. for tenminutes, during which time it became homogeneous. The mixture was thenpoured into ice-water, and the resulting mixture was extracted withethyl acetate. The extract was washed in succession with a saturatedaqueous solution of sodium bicarbonate and a saturated aqueous solutionof sodium chloride. The extract was dried over anhydrous magnesiumsulfate and filtered. The solvent was evaporated from the filtrate underreduced pressure, leaving a residue. This residue was placed on a columnof silica gel and eluted with ethyl acetate/hexane (1:1). After theproduct-containing fractions were combined and the solvents evaporatedunder reduced pressure, 1.38 g of2-(4-hydroxy-2-fluorophenyl)-4-methyl-1,2,4-triazine-3,5-dione wasrecovered as a stiff syrup. The NMR was consistent with the proposedstructure.

Step I: Methyl2-[2-[4-(4-methyl-1,2,4-triazine-3,5-dion-2-yl)-3-fluorophenoxymethyl]-5-methylphenoxy]propionate

By the method of Example 1, Step K, 0.47 g (0.002 mole) of2-(4-hydroxy-2-fluorophenyl)-4-methyl-1,2,4-triazine-3,5-dione and 0.73g (0.003 mole) of methyl 2 -(2-chloromethyl-5-methylphenoxy)propionatewere reacted in the presence of 0.41 g (0.003 mole) of anhydrouspotassium carbonate in 30 mL of N,N-dimethylformamide, yielding 0.70 gof methyl2-[2-[4-(4-methyl-1,2,4-triazine-3,5-dion-2-yl)-3-fluorophenoxymethyl]-5-methylphenoxy]propionateas a syrup. The IR and NMR spectra were consistent with the proposedstructure. NMR: 1.60 (d, 3H, J_(HH) =8.0 Hz); 2.30 (s, 3H); 3.40 (s,3H); 3.78 (s, 3H); 4.84 (q, 1H, J_(HH) =8.0 Hz); 5.18 (dd, 2H, J_(HH)=10 Hz); 6.58 (s, 1H); 6.8-7.3 (m, 5H); 7.54 (s, 1H).

EXAMPLE 7 METHYL2-[2-[4-(4-DIFLUOROMETHYL-4,5-DIHYDRO-3-METHYL-1,2,4-TRIAZOL-5(1H)-ON-1-YL)-3-FLUOROPHENYLTHIOMETHYL]-5-CHLOROPHENOXY]PROPIONATE(Compound 72)

Step A4-(4-Difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenylsulfonylchloride

A mixture of 2.02 g (0.0078 mole) of1-(2-fluoro-4-aminophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4,-triazol-5(1H)-one(Example 1, Step E) in 20 mL of hydrochloric acid was cooled to 0° C.,and 0.55 g (0.0084 mole) of sodium nitrite in 5 mL of water was addedslowly while the temperature was held at 0°-5° C. The yellow solutionwas then stirred at room temperature for two hours. Meanwhile a solutionof 1.08 g (0.0080 mole) of copper(II) chloride in 5 mL of water and 20mL of acetic was prepared, and sulfur dioxide was bubbled through thissolution until it was saturated, a period of ten minutes. After havingbeen stirred for two hours, the yellow solution was added slowly to thesolution saturated with sulfur dioxide. The mixture turned green, and ayellow precipitate formed. During the addition, the temperature rose to32° C. The reaction mixture was stirred for an hour at room temperatureand then poured over ice. The pale yellow solid that formed was isolatedby filtration, yielding 1,86 g of4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenylsulfonylchloride. The NMR spectrum was consistent with the proposed structure.This reaction was repeated to obtain additional product for subsequentreactions.

Step B4-(4-Difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorothiophenol

Gaseous hydrogen chloride was bubbled into a mixture of 3.29 g (0.0146mole) of tin(II) chloride in 40 mL of acetic acid for about fiveminutes, causing it to become a clear solution. This solution was thenheated to 85° C., and a hot solution of 1.66 g (0.00485 mole) of4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenylsulfonylchloride was added to the first solution. This reaction mixture washeated at 85° C. for 45 minutes. After cooling to room temperature, theresulting yellow solution was poured into 120 mL of hydrochloric acid.To this mixture was added 100 mL of a saturated aqueous solution ofsodium chloride, and the resulting mixture was extracted with ethylacetate, but the layers did not separate. The addition of a saturatedaqueous solution of sodium chloride did effect a partial separation. Theaqueous layer was extracted two more times with ethyl acetate, and allextracts were combined. After evaporation of the solvent under reducedpressure, the residue retained an odor of hydrochloric acid. Water wasadded to the residue, and this mixture was extracted three times withethyl acetate. The combined extracts were washed with water, dried overanhydrous magnesium sulfate, and filtered. Following evaporation of thesolvent under reduced pressure, the yellow residue that remained wasdried under vacuum. This dried residue was placed on a column of silicagel and eluted with methylene chloride/ethyl acetate (2:1). After beingdried under vacuum for several hours, 0.81 g of4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorothiophenolwas isolated as a yellow syrup. The NMR spectrum was consistent with theproposed structure. This reaction was repeated to obtain additionalproduct for subsequent reactions.

Step C Methyl2-[2-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenylthiomethyl]-5-chlorophenoxy]propionate

By the method of Example 1, Step K, 1.35 g (0.0049 mole) of4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorothiophenoland 3.0 g (0.011 mole) of methyl2-(2-chloromethyl-5-chlorophenoxy)propionate (Example 2, Step F) werereacted in the presence of 1.02 g (0.0074 mole) of anhydrous potassiumcarbonate in 75 mL of N,N-dimethylformamide, yielding 0.54 g of methyl2-[2-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenylthiomethyl]-5-chlorophenoxy]propionateas a yellow syrup. The NMR spectrum was consistent with the proposedstructure. NMR: 1.65 (d, 3H, J_(HH) =8.0 Hz); 2.44 (s, 3H); 3.78 (s,3H); 4.20 (dd, 2H, J_(HH) =13.0 Hz); 4.78 (q, 1H, J_(HH) =8.0 Hz);6.70-7.38 (m, 7H).

EXAMPLE 8 METHYL[2-[4-(4-DIFLUOROMETHYL-4,5-DIHYDRO-3-METHYL-1,2,4-TRIAZOL-5(1H)-ON-1-YL)-3-FLUOROPHENOXYMETHYL]-5-METHYLPHENOXY]ACETATE(Compound 75)

Step A Methyl (2-formyl-5-methylphenoxy)acetate

By the method of Example 1, Step H, 8,27 g (0.060 mole) of4-methylsalicylaldehyde (Example 1, Step G) and 11.15 g (0.073 mole) ofmethyl bromoacetate were reacted in the presence of 10.1 g (0.073 mole)of anhydrous potassium carbonate in 150 mL of acetone, yielding 11.47 gof methyl (2-formyl-5-methylphenoxy)acetate as a white solid, m. p.63°-64° C. The NMR was consistent with the proposed structure.

Step B Methyl (2-hydroxymethyl-5-methylphenoxy)acetate

By the method of Example 1, Step I, 11.27 g (0.054 mole) of methyl(2-formyl-5-methylphenoxy)acetate was reacted with 0.54 g (0.014 mole)of sodium borohydride and 0.10 g (0.0018 mole) of sodium methoxide in 30mL of methanol, yielding 9.41 g of methyl(2-hydroxymethyl-5-methylphenoxy)acetate as a yellow oil. The NMRspectrum was consistent with the proposed structure.

Step C Methyl (2-chloromethyl-5-methylphenoxy)acetate

By the method of Example 1, Step J, 9.21 g (0.044 mole) of methyl(2-hydroxymethyl-5-methylphenoxy)acetate was reacted with 7.40 g (0.062mole) of thionyl chloride and 5 drops of pyridine in 50 mL of methylenechloride, yielding 5.57 g of methyl(2-chloromethyl-5-methylphenoxy)acetate as an orange liquid.

Step D Methyl[2-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]-5-methylphenoxy]acetate

By the method of Example 1, Step K, 2.0 g (0.0077 mole) of1-(2-fluoro-4-hydroxyphenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one(Example 1, Step F) and 3.53 g (0.0151 mole) of methyl(2-chloromethyl-5-methylphenoxy)acetate were reacted in the presence of1.60 g (0.0116 mole) of anhydrous potassium carbonate in 40 mL ofN,N-dimethylformamide, yielding 2.75 g of methyl[2-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]-5-methylphenoxy]acetate.The NMR spectrum was consistent with the proposed structure. NMR: 2.30(s, 3H); 2.44 (s, 3H); 3.78 (s, 3H); 4.70 (s, 2H); 5.18 (s, 2H);6.60-7.36 (m, 7H).

EXAMPLE 92-[3-[4-(4-DIFLUOROMETHYL-4,5-DIHYDRO-3-METHYL-1,2,4-TRIAZOL-5(1H)-ON-1-YL)-3-FLUOROPHENOXYMETHYL]PHENOXY]PROPIONATE(Compound 80)

Step A Methyl 2-(3-formylphenoxy)propionate

By the method of Example 1, Step H, 10.0 g (0.0819 mole) of3-hydroxybenzaldehyde and 16.0 g (0.0982 mole) of methyl2-bromopropionate were reacted in the presence of 13.6 g (0.0983 mole)of anhydrous potassium carbonate in 50 mL of N,N-dimethylformamide,yielding 16.1 g of methyl 2-(3-formylphenoxy)propionate as an orangeliquid. The NMR and IR spectra were consistent with the proposedstructure.

Step B Methyl 2-(3-hydroxymethylphenoxy)propionate

By the method of Example 1, Step I, 15.7 g (0.0761 mole) of methyl2-(3-formylphenoxy)propionate, 0.76 g (0.020 mole) of sodiumborohydride, and 0.10 g (0.0018 mole) of sodium methoxide were reactedin 40 mL of methanol, yielding 15.6 g of methyl2-(3-hydroxymethylphenoxy)propionate as a yellow liquid. The NMR and IRspectra were consistent with the proposed structure.

Step C Methyl 2-(3-chloromethylphenoxy)propionate

By the method of Example 1, Step J, 1.98 g (0.0095 mole) of methyl2-(3-hydroxymethylphenoxy)propionate and 1.24 g (0.0105 mole) of thionylchloride were reacted in the presence of five drops of pyridine in 40 mLof methylene chloride, yielding 1.93 g of methyl2-(3-chloromethylphenoxy)propionate as a yellow liquid. The NMR and IRspectra were consistent With the proposed structure.

Step D Methyl2-[3-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]phenoxy]propionate

By the method of Example 1, Step K, 1.0 g (0.0038 mole) of1-(2-fluoro-4-hydroxyphenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one(Example 1, Step F) and 1.72 g (0.0076 mole) of methyl2-(3-chloromethylphenoxy)propionate were reacted in the presence of 0.79g (0.0057 mole) of anhydrous potassium carbonate in 25 mL ofN,N-dimethylformamide, yielding 1.54 g of methyl2-[3-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]phenoxy]propionate.The NMR and IR spectra were consistent with the proposed structure. NMR:1.60 (d, 3H, J_(HH) =8.0 Hz); 2.44 (s, 3H); 3.76 (s, 3H); 4.78 (q, 1H,J_(HH) =8.0 Hz); 5.04 (s, 2H); 6.76-7.38 (m, 8H).

EXAMPLE 10 METHYL 2-[4-[4-(4-DIFLUOROMETHYL-4,5-DIHYDRO-3-METHYL-1,2,4-TRIAZOL-5(1H)-ON-1-YL)-3-FLUOROPHENOXYMETHYL]PHENOXY]PROPIONATE(Compound 81)

Step A Methyl 2-(4-formylphenoxy)propionate

By the method of Example 1, Step H, 10.0 g (0.0819 mole) of4-hydroxybenzaldehyde and 16.4 g (0.0983 mole) of methyl2-bromopropionate were reacted in the presence of 13.6 g (0.0983 mole)of anhydrous potassium carbonate in N,N-dimethylformamide, yielding 12.2g of methyl 2-(4-formylphenoxy)propionate as a yellow liquid. The NMRand IR spectra were consistent with the proposed structure.

Step B Methyl 2-(4-hydroxymethylphenoxy)propionate

By the method of Example 1, Step I, 11.1 g (0.0533 mole) of methyl2-(4-formylphenoxy)propionate and 2.02 g (0.0533 mole) of sodiumborohydride were reacted in methanol, yielding 9.31 g of methyl2-(4-hydroxymethylphenoxy)propionate as a yellow oil. The NMR spectrumwas consistent with the proposed structure.

Step C Methyl 2-(4-chloromethylphenoxy)propionate

A mixture of 2.19 g (0.0104 mole) of methyl2-(4-hydroxymethylphenoxy)propionate and 3.00 g (0.0823 mole) of 36%hydrochloric acid was stirred for fifteen minutes at room temperature.The reaction mixture was then poured into ice-water, and the resultingmixture was extracted with diethyl ether. The extracts were combined andwashed in succession with water and a saturated aqueous solution ofsodium bicarbonate. The extract was dried over anhydrous magnesiumsulfate and filtered, and the solvent was evaporated from the filtrateunder reduced pressure, leaving a colorless liquid. This liquid wasplaced on a column of silica gel and eluted with methylene chloride.After the product-containing fractions were combined and the solventevaporated under reduced pressure, 1.6 g of methyl2-(4-chloromethylphenoxy)propionate was isolated as a colorless liquid.The NMR and IR spectra were consistent with the proposed structure.

Step D Methyl2-[4-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]phenoxy]propionate

By the method of Example 1, Step K, 0.50 g (0.0019 mole) of1-(2-fluoro-4-hydroxyphenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-one(Example 1, Step F) and 0.87 g (0.0038 mole) of methyl2-(4-chloromethylphenoxy)propionate were reacted in the presence of 0.2g of 1,4,7,10,13,16-hexaoxacyclooctadecane in 25 mL ofN,N-dimethylformamide, yielding 0.80 g of methyl2-[4-[4-(4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl)-3-fluorophenoxymethyl]phenoxy]propionate as a colorless oil that solidified upon standing,m.p. 83°-85° C. The NMR and IR spectra were consistent with the proposedstructure. NMR: 1.60 (d, 3H, J_(HH) =8.0 Hz); 2.44 (s, 3H); 3.76 (s,3H); 4.78 (q, 1H, J_(HH) =8.0 Hz); 4.90 (s, 2H); 6.78-7.38 (m, 8H).

EXAMPLE 11 METHYL2-[2-[4-(8-THIA-1,6-DIAZABICYCLO[4.3.0]NONANE-7-ON-9-YLIMINO)-3-FLUOROPHENOXYMETHYL]-5-METHYLPHENOXY]PROPIONATE(Compound 68)

Step A Methyl2-[2-(3-fluoro-4-nitrophenoxymethyl)-5-methylphenoxy]propionate

By the method of Example 1, Step K, 1.71 g (0.010 mole) of3-fluoro-4-nitrophenol and 2.85 g (0.011 mole) of methyl2-(2-chloromethyl-5-methylphenoxy)propionate were reacted in thepresence of 1.66 g (0.012 mole) of anhydrous potassium carbonate in 100mL of N,N-dimethylformamide, yielding 3.55 g of methyl2-[2-(3-fluoro-4-nitrophenoxymethyl)-5-methylphenoxy]propionate as ayellowish solid, m.p. 92°-94° C. The NMR and IR spectra were consistentwith the proposed structure.

Step B Methyl2-[2-(4-amino-3-fluorophenoxymethyl)-5-methylphenoxy]propionate

By the method of Example 2, Step A, 3.35 g (0.0091 mole) of methyl2-[2-(3-fluoro-4-nitrophenoxymethyl)-5-methylphenoxy]propionate wasreacted with 2.80 g (0.050 mole) of powdered iron in 100 mL of aceticacid, yielding 1.86 g of methyl2-[2-(4-amino-3-fluorophenoxymethyl)-5-methylphenoxy]propionate as anamber syrup. The NMR and IR spectra were consistent with the proposedstructure.

Step C Methyl2-[2-(3-fluoro-4-isothiocyanatophenoxymethyl)-5-methylphenoxy]propionate

A solution of 1.66 g (0.005 mole) of methyl 2-[2-(4-amino-3-fluorophenoxymethyl)-5-methylphenoxy]propionate and 1.26 g(0.0125 mole) of triethylamine in 40 mL of methylene chloride wasprepared at ambient temperature. To this solution was added dropwise asolution of 0.58 g (0.0050 mole) of thiophosgene in 10 mL of methylenechloride. The reaction mixture was stirred for 16 hours after which itwas filtered through a short column of silica gel. The solvent wasevaporated from the filtrate under reduced pressure, leaving 1.50 g ofmethyl2-[2-(3-fluoro-4-isothiocyanatophenoxymethyl)-5-methylphenoxy]propionateas a syrup. The NMR and IR spectra were consistent with the proposedstructure.

Step D Methyl2-[2-[4-(perhydropyridazin-1-ylthiocarbonylamino)-3-fluorophenoxymethyl]-5-methylphenoxy]propionate

By the method of Example 1, Step C, of U.S. Pat. No. 4,906,281, 1.50 g(0.004 mole) of methyl2-[2-(3-fluoro-4-isothiocyanatophenoxymethyl)-5-methylphenoxy]propionateand 1.07 g (0.005 mole) of perhydropyridazine monohydroiodide (preparedby the method of Example 1, Step B, of U.S. Pat. No. 4,906,281) werereacted in the presence of 0.20 g (0.0050 mole of sodium hydroxide in 40mL of water and 10 ML of tetrahydrofuran, yielding 1.50 g of methyl2-[2-[4-(perhydropyridazin-1-ylthiocarbonylamino)-3-fluorophenoxymethyl]-5-methylphenoxy]propionateas a syrup. The NMR spectrum was consistent with proposed structure.

Step E Methyl2-[2-[4-(8-thia-1,6-diazabicyclo[4.3.0]nonane-7-on-9-ylimino)-3-fluorophenoxymethyl]-5-methylphenoxy]propionate

By the method of Example 1, Step D, of U.S. Pat. No. 4,906,281, 1.50 g(0.00325 mole) of methyl2-[2-[4-(perhydropyridazin-1-ylthiocarbonylamino)-3-fluorophenoxymethyl]-5-methylphenoxy]propionateand 0.36 g (0.09017 mole) of trichloromethyl chloroformate were reactedin the presence of 0.36 g (0.0035 mole) of triethylamine in 35 mL ofdioxane, yielding 0.50 g of methyl2-[2-[4-(8-thia-1,6-diazabicyclo[4.3.0]nonane-7-on-9-ylimino)-3-fluorophenoxymethyl]-5-methylphenoxy]propionateas a syrup. The NMR and IR spectra were consistent with the proposedstructure. NMR: 1.60 (d, 3H, J_(HH) =8.0 Hz); 1.78-1.96 (m, 4H); 2.30(s, 3H); 3.64-3.80 (m, 4H): 3.70 (s, 3H); 4.80 (q, 1H, J_(HH) =8.0 Hz);5.10 dd, 2H); 6.58-7.30 (m, 6H).

Representative compounds of the invention prepared by the methodsexemplified above are shown in Table 1.

HERBICIDAL ACTIVITY

The2-[(4-heterocyclic-substituted-3-halophenoxymethyl)phenoxy]alkanoates ofthis invention were tested in pre- and postemergence evaluations using avariety of broadleaf and grasseous crops and weeds. The test speciesused to demonstrate the herbicidal activity of these compounds includesoybean (Glycine max var. Williams), field corn (Zea mays var. Agway425X), wheat (Triticum aestivum var. Wheaton), morningglory (Ipomealacunosa or Ipomea hederacea), velvetleaf (Abutilon theophrasti), greenfoxtail (Setaria viridis), Johnsongrass (Sorphum halepense), blackgrass(Alopecurus myosuroides), common chickweed (Stellaria media), and commoncocklebur (Xanthium pensylvanicum).

Preparation of Flats

For preemergence testing two disposable fiber flats (8 cm×15 cm×25 cm)for each rate of application of each candidate herbicide were filled toan approximate depth of 6.5 cm with steam-sterilized sandy loam soil.The soil was leveled and impressed with a template to provide fiveevenly spaced furrows 13 cm long and 0.5 cm deep in each flat. Seeds ofsoybean, wheat, corn, green foxtail, and Johnsongrass were planted inthe furrows of the first flat, and seeds of velvetleaf, morningglory,common chickweed, cocklebur, and blackgrass were planted in the furrowsof the second flat. The five-row template was employed to firmly pressthe seeds into place. A topping soil of equal portions of sand and sandyloam soil was placed uniformly on top of each flat to a depth ofapproximately 0.5 cm. Flats for postemergence testing were prepared inthe same manner, except that they were planted 8-12 days prior to thepreemergence flats and were placed in a greenhouse and watered, thusallowing the seeds to germinate and the foliage to develop.

A stock solution of the candidate herbicide was prepared by dissolving apredetermined weight of the compound in 20 ml of water/acetone (50/50)containing 0.5% v/v sorbitan monolaurate. Thus for an application rateof 3000 g/ha of herbicide, 0.21 g of candidate herbicide was dissolvedin 20 ml of the aqueous acetone to prepare the stock solution. For the300 g/ha rate of application used in most of the tests reported below, a1.0 mL portion of stock solution was diluted with water/acetone (50/50)to 35 ml, the volume required for a spray volume of 1000 L/ha. Theremaining stock solution was then used to prepare spray solutions forother application rates.

The spray solution (35 ml) was then sprayed on the four flatssimultaneously, i.e., to the surface of the soil of the preemergenceflats and to the emerged foliage of the postemergence flats. All flatswere placed in the greenhouse, but only the preemergence flats werewatered immediately. The foliage of the postemergence flats was kept dryfor 24 hours, after which regular watering commenced. Phytotoxicitydata, taken as percent control, were recorded 17-21 days after thechemical was applied.

Percent control was determined by a method similar to the 0 to 100rating system disclosed in "Research Methods in Weed Science," 2nd ed.,B. Truelove, Ed.; Southern Weed Science Society; Auburn University,Auburn, Ala., 1977. The rating system is as follows:

    ______________________________________                                        Herbicide Rating System                                                       Rating Description                                                            Percent                                                                              of Main   Crop          Weed                                           Control                                                                              Categories                                                                              Description   Description                                    ______________________________________                                         0     No effect No crop       No weed                                                         reduction     control                                                         or injury                                                    10     Slight    Slight dis-   Very poor weed                                        effect    coloration    control                                                         or stunting                                                  20               Some dis-     Poor weed                                                       coloration,   control                                                         stunting or                                                                   stand loss                                                   30               Crop injury   Poor to defi-                                                   more pronounced                                                                             cient weed                                                      but not lasting                                                                             control                                        40     Moderate  Moderate injury,                                                                            Deficient weed                                        effect    crop usually  control                                                         recovers                                                     50               Crop injury   Deficient to                                                    more lasting, moderate weed                                                   recovery doubtful                                                                           control                                        60               Lasting crop  Moderate weed                                                   injury, no    control                                                         recovery                                                     70     Severe    Heavy injury and                                                                            Control some-                                                   stand loss    what less than                                                                satisfactory                                   80               Crop nearly des-                                                                            Satisfactory                                                    troyed, a few to good weed                                                    survivors     control                                        90               Only occasional                                                                             Very good to                                                    live plants left                                                                            excellent                                      control                                                                       100    Complete  Complete crop Complete weed                                         effect    destruction   destruction                                    ______________________________________                                    

Herbicidal data at 300 or 250 presented in Table 2 (preemergenceactivity) and Table 3 (post-emergence activity). The test compounds areidentified in Tables 2 and 3 by numbers which correspond to those inTable 1.

For herbicidal application the active compounds are formulated intoherbicidal compositions by admixture in herbicidally effective amountswith adjuvants and carriers normally employed in the art forfacilitating the dispersion of active ingredients for the particularutility desired, recognizing the fact that the formulation and mode ofapplication of a toxicant may affect the activity of the material in agiven application. Thus, for agricultural use the present herbicidalcompounds may be formulated as granules of relatively large particlesize, as water-soluble or water-dispersible granules, as powdery dusts,as wettable powders, as emulsifiable concentrates, as solutions, or asany of several other known types of formulations, depending on thedesired mode of application.

These herbicidal compositions may be applied either as water-dilutedsprays, or dusts, or granules to the areas in which suppression ofvegetation is desired. These formulations may contain as little as 0.1%,0.2% or 0.5% to as much as 95% or more by weight of active ingredient.

Dusts are free flowing admixtures of the active ingredient with finelydivided solids such as talc, natural clays, kieselguhr, flours such aswalnut shell and cottonseed flours, and other organic and inorganicsolids which act as dispersants and carriers for the toxicant; thesefinely divided solids have an average particle size of less than about50 microns. A typical dust formulation useful herein is one containing1.0 part or less of the herbicidal compound and 99.0 parts of talc.

Wettable powders, also useful formulations for both pre- andpostemergence herbicides, are in the form of finely divided particleswhich disperse readily in water or other dispersant. The wettable powderis ultimately applied to the soil either as a dry dust or as an emulsionin water or other liquid. Typical carriers for wettable powders includeFuller's earth, kaolin clays, silicas, and other highly absorbent,readily wet inorganic diluents. Wettable powders normally are preparedto contain about 5-80% of active ingredient, depending on the absorbencyof the carrier, and usually also contain a small amount of a wetting,dispersing or emulsifying agent to facilitate dispersion. For example, auseful wettable powder formulation contains 80.8 parts of the herbicidalcompound, 17.9 parts of Palmetto clay, and 1.0 part of sodiumlignosulfonate and 0.3 part of sulfonated aliphatic polyester as wettingagents. Frequently additional wetting agent and/or oil will be added tothe tank mix for postemergence application to facilitate dispersion onthe foliage and absorption by the plant.

Other useful formulations for herbicidal applications are emulsifiableconcentrates (ECs) which are homogeneous liquid compositions dispersiblein water or other dispersant, and may consist entirely of the herbicidalcompound and a liquid or solid emulsifying agent, or may also contain aliquid carrier, such as xylene, heavy aromatic naphthas, isophorone, orother non-volatile organic solvent. For herbicidal application theseconcentrates are dispersed in water or other liquid carrier, andnormally applied as a spray to the area to be treated. The percentage byweight of the essential active ingredient may vary according to themanner in which the composition is to be applied, but in generalcomprises 0.5 to 95% of active ingredient by weight of the herbicidalcomposition.

Flowable formulations are similar to ECs except that the activeingredient is suspended in a liquid carrier, generally water. Flowables,like ECs, may include a small amount of a surfactant, and contain activeingredient in the range of 0.5 to 95%, frequently from 10 to 50%, byweight of the composition. For application, flowables may be diluted inwater or other liquid vehicle, and are normally applied as a spray tothe area to be treated.

Typical wetting, dispersing, or emulsifying agents used in agriculturalformulations include, but are not limited to, the alkyl and alkylarylsulfonates and sulfates and their sodium salts; alkylaryl polyetheralcohols; sulfated higher alcohols; polyethylene oxides; sulfonatedanimal and vegetable oils; sulfonated petroleum oils; fatty acid estersof polyhydric alcohols and the ethylene oxide addition products of suchesters; and the addition product of long-chain mercaptans and ethyleneoxide. Many other types of useful surface-active agents are available incommerce. The surface-active agent, when used, normally comprises from 1to 15% by weight of the composition.

Other useful formulations include suspensions of the active ingredientin a relatively non-volatile liquid such as water, corn oil, kerosene,propylene glycol, or other suitable liquid carrier.

Still other useful formulations for herbicidal applications includesimple solutions of the active ingredient in a solvent in which it iscompletely soluble at the desired concentration, such as acetone,alkylated naphthalenes, xylene, or other organic solvents. Granularformulations, wherein the toxicant is carried on relatively coarseparticles, are of particular utility for aerial distribution or forpenetration of cover crop canopy. Pressurized sprays, typically aerosolswherein the active ingredient is dispersed in finely divided form as aresult of vaporization of a low boiling dispersant solvent carrier, suchas the Freon fluorinated hydrocarbons, may also be used. Water-solubleor water-dispersible granules are also useful formulations forherbicidal application of the present compounds. Such granularformulations are free-flowing, non-dusty, and readily water-soluble orwater-miscible. The soluble or dispersible granular formulationsdescribed in U.S. Pat. No. 3,920,442 are useful with the presentherbicidal compounds. In use by the farmer on the field, the granularformulations, emulsifiable concentrates, flowable concentrates,solutions, etc., may be diluted with water to give a concentration ofactive ingredient in the range of say 0.1% or 0.2% to 1.5% or 2%.

The active herbicidal compounds of this invention may be formulatedand/or applied with insecticides, fungicides, nematicides, plant growthregulators, fertilizers, or other agricultural chemicals and may be usedas effective soil sterilants as well as selective herbicides inagriculture. In applying an active compound of this invention, whetherformulated alone or with other agricultural chemicals, an effectiveamount and concentration of the active compound is of course employed;the amount may be as low as, e.g. about 10 to 100 g/ha, preferably about30 to 60 g/ha. For field use, where there are losses of herbicide,higher application rates (e.g., four times the greenhouse testing ratesmentioned above) may be employed.

The active herbicidal compounds of this invention may be used incombination with other herbicides, e.g. they may be mixed with, say, alesser, equal, or larger amount of a known herbicide such aschloroacetanilide herbicides such as2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide (alachlor),2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide(metolachlor), and N-chloroacetyl-N-(2,6-diethylphenyl)glycine(diethatyl ethyl); benzothiadiazinone herbicides such as3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4-(3H)-one-2,2-dioxide(bentazon): triazine herbicides such as6-chloro-N-ethyl-N-(1-methylethyl)-1,3,5-triazine-2,4-diamine(atrazine), and2-[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino-2-methylpropanenitrile(cyanazine); dinitroaniline herbicides such as2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzeneamine (trifluralin);aryl urea herbicides such as N'-(3,4-dichlorophenyl)-N,N-dimethylurea(diuron) and N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl]urea(fluometuron); and2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone.

It is apparent that various modifications may be made in the formulationand application of the compounds of this invention without departingfrom the inventive concepts herein as defined in the claims.

                                      TABLE 1                                     __________________________________________________________________________    Compound                                                                      No.   Q.sup.a                                                                          X    Y    Z    Z'  R                                                 __________________________________________________________________________     ##STR16##                                                                    R' = CH.sub.3, W = O                                                           1    A  H    H    H    H   CH.sub.3                                           2    A  F    H    H    H   H                                                  3    A  F    H    H    H   CH.sub.3                                           4    A  F    H    4-F  H   CH.sub.3                                           5    A  F    H    3-Cl H   CH.sub.3                                           6    A  F    H    4-Cl H   H                                                  7    A  F    H    4-Cl H   CH.sub.3                                           8    A  F    H    5-Cl H   CH.sub.3                                           9    A  F    H    4-Br H   CH.sub.3                                          10    A  F    H    3-F  4-F CH.sub.3                                          11    A  F    H    3-Cl 4-Cl                                                                              CH.sub.3                                          12    A  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          13    A  F    H    5-OCH.sub.3                                                                        H   CH.sub.3                                          14    A  Cl   H    H    H   CH.sub.3                                          15    A  Cl   H    H    H   CH.sub.3 O(CH.sub.2).sub.2 O(CH.sub.2).sub.2      16    A  Cl   H    4-F  H   CH.sub.3                                          17    A  Cl   H    3-Cl H   CH.sub.3                                          18    A  Cl   H    4-Cl H   CH.sub.3                                          19    A  Cl   H    4-Br H   CH.sub.3                                          20    A  Cl   H    3-F  4-F CH.sub.3                                          21    A  Cl   H    3-Cl 4-Cl                                                                              CH.sub.3                                          22    A  Cl   H    4-CH.sub.3                                                                         H   CH.sub.3                                          23    B  H    H    H    H   CH.sub.3                                          24    B  F    H    H    H   CH.sub.3                                          25    B  F    H    4-F  H   CH.sub.3                                          26    B  F    H    3-Cl H   CH.sub.3                                          27    B  F    H    4-Cl H   CH.sub.3                                          28    B  F    H    5-Cl H   CH.sub.3                                          29    B  F    H    4-Br H   CH.sub.3                                          30    B  F    H    3-F  4-F CH.sub.3                                          31    B  F    H    3-Cl 4-Cl                                                                              CH.sub.3                                          32    B  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          33    B  Cl   H    4-F  H   CH.sub.3                                          34    B  Cl   H    3-Cl H   CH.sub.3                                          35    B  Cl   H    4-Cl H   CH.sub.3                                          36    B  Cl   H    4-Br H   CH.sub.3                                          37    B  Cl   H    3-Cl 4-Cl                                                                              CH.sub.3                                          38    B  Cl   H    4-CH.sub.3                                                                         H   CH.sub.3                                          39    B  3-OC(CH.sub.3).sub.2 CH.sub.2 -2                                                        H    H   CH.sub.3                                          40    B  3-OC(CH.sub.3).sub.2 CH.sub.2 -2                                                        4-Cl H   CH.sub.3                                          41    C  F    H    H    H   CH.sub.3                                          42    C  F    H    4-F  H   CH.sub.3                                          43    C  F    H    3-Cl H   CH.sub.3                                          44    C  F    H    4-Cl H   CH.sub.3                                          45    C  F    H    3-Cl 4-Cl                                                                              CH.sub.3                                          46    A  F    H    4-Cl 6-Cl                                                                              CH.sub.3                                          47    A  F    H    4-CH.sub.3                                                                         H   H                                                 48    A  F    H    4-CH.sub.3                                                                         H   C.sub.2 H.sub.5                                   49    A  F    H    4-CH.sub.3                                                                         H    .sub.- i-C.sub.3 H.sub.7                         50    A  F    H    4-C.sub.2 H.sub.5                                                                  H   H                                                 51    A  F    H    4-C.sub.2 H.sub.5                                                                  H   CH.sub.3                                          52    A  F    H    4-C.sub.3 H.sub.7                                                                  H   CH.sub.3                                          53    A  F    H    4- .sub.- i-C.sub.3 H.sub.7                                                        H   CH.sub.3                                          54    A  F    H    4-C.sub.4 H.sub.9                                                                  H   CH.sub.3                                          55    A  F    H    4- .sub.- t-C.sub.4 H.sub.9                                                        H   CH.sub.3                                          56    A  F    H    4-C.sub.2 H.sub.5                                                                  H   CH.sub.3 OCH.sub.2 CH(CH.sub.3)                   57    A  F    H    4-CH.sub.3                                                                         H   CH.sub.3 O(CH.sub.2).sub.2 O(CH.sub.2).sub.2      58    A  F    H    4-C.sub.2 H.sub.5                                                                  H   CH.sub.3 O(CH.sub.2).sub.2 O(CH.sub.2).sub.2      59    A  F    H    4- .sub.- t-C.sub.4 H.sub.9                                                        H   CH.sub.3 O(CH.sub.2).sub.2 O(CH.sub.2).sub.2      60    A  F    H    4-φ                                                                            H   CH.sub.3                                          61    A  F    H    3-(CH.sub.2).sub.4 -4                                                                  CH.sub.3                                          62    A  Cl   H    4-C.sub.2 H.sub.5                                                                  H   CH.sub.3                                          63    D  F    H    4-Cl H   CH.sub.3                                          64    D  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          65    D  F    H    4-C.sub.2 H.sub.5                                                                  H   CH.sub.3                                          66    E  F    H    4-Cl H   CH.sub.3                                          67    E  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          68    F  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          69    G  F    H    4-Cl H   CH.sub.3                                          70    G  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          71    G  F    H    4-C.sub.3 H.sub.7                                                                  H   CH.sub.3                                          R' = CH.sub.3, W = S                                                          72    A  F    H    4-Cl H   CH.sub.3                                          73    A  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          R' = H, W = O                                                                 74    A  F    H    H    H   CH.sub.3                                          75    A  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                          76    A  F    H    4-CH.sub.3                                                                         H   H                                                 77    B  F    H    H    H   CH.sub.3                                          78    D  F    H    4-CH.sub.3                                                                         H   CH.sub.3                                           ##STR17##                                                                    R' = CH.sub.3, W = O                                                          79    A  F    H    H    H   H                                                 80    A  F    H    H    H   CH.sub.3                                           ##STR18##                                                                    R' = CH.sub.3, W = O                                                          81    A  F    H    H    H   CH.sub.3                                          82    A  F    H    H    H   CH.sub.3 O(CH.sub.2).sub.2 O(CH.sub.2).sub.2      83    A  Cl   H    H    H   CH.sub.3                                          84    B  F    H    H    H   CH.sub.3                                          __________________________________________________________________________     ##STR19##                                                                     ##STR20##                                                                     ##STR21##                                                                     ##STR22##                                                                     ##STR23##                                                                     ##STR24##                                                                     ##STR25##                                                                

    TABLE 2                                                                       __________________________________________________________________________    PREEMERGENCE HERBICIDAL ACTIVITY (% Control)                                         Compound No.                                                                  1   2   3   4   5   6   7   8   9   10  11  12  13  14*                       Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.25                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              0   0   90  80  10  10  50  0   100 10  0   20  0   0                  Wheat  70  80  20  80  10  50  95  0   80  20  10  70  0   5                  Corn   15  15  15  70  20  85  10  5   95  10  10  50  5   10                 Velvetleaf                                                                           100 100 100 100 100 100 100 85  100 100 100 100 100 85                 Morningglory                                                                         100 100 100 100 100 100 100 85  100 95  100 100 60  70                 Chickweed                                                                            90  80  90  100                                                        00     100 100 90  100 100 100 100 20  45                                     Cocklebur                                                                            10  20  70  80  70  100 100 0   100 40  60  90  30  0                  Blackgrass                                                                           80  40  70  95  90  100 100 0   100 70  20  80  0   0                  Green foxtail                                                                        90  80  100 100 100 100 100 10  100 100 100 100 85  75                 Johnsongrass                                                                         80  70  70  95  95  80  70  40  95  40  90  60  10  30                 __________________________________________________________________________     *Average of two tests  where average is not a multiple of five, given as      next lower multiple of five.                                             

    Compound No.                                                                         15  16  17  18  19  20  21  22  23  24  25  26  27  28                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.25                                                                              0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              0   10  10  0   60  0   0   10  --  5   20  0   10  90                 Wheat  5   10  70  10  --  0   0   60  5   10  20  0   0   95                 Corn   5   15  10  30  20  0   30  50  5   5   10  0   15  95                 Velvetleaf                                                                           100 100 100 100 100 100 100 100 30  80  100 85  100 50                 Morningglory                                                                         100 100 30  90  90  80  70  90  100 70  100 95  100 20                 Chickweed                                                                            90  100 40  100 100 50  20  80  85  95  100 --  100 85                 Cocklebur                                                                            5   60  20  40  60  0   20  10  0   20  80  10  80  0                  Blackgrass                                                                           0   20  80  10  90  10  10  30  5   90  0   40  70  60                 Green foxtail                                                                        50  100 90  100 100 100 95  95  40  30  60  20  0   15                 Johnsongrass                                                                         0   60  95  90  90  60  70  50  60  15  10  0   40  85                 __________________________________________________________________________           Compound No.                                                                  29  30  31  32  33  34  35  36  37  38  39  40  41  42                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              90  40  10  30  0   0   0   0   0   0   10  10  0   0                  Wheat  0   0   0   0   0   0   0   0   0   0   --  10  0   0                  Corn   20  0   0   0   15  0   10  0   0   0   --  0   0   50                 Velvetleaf                                                                           100 100 100 100 100 95  100 100 80  70  0   0   --  0                  Morningglory                                                                         100 90  95  100 100 90  95  80  60  20  10  0   10  0                  Chickweed                                                                            100 95  10  100 100 --  95  100 0   50  --  100 0   0                  Cocklebur                                                                            85  100 20  80  10  10  10  20  0   10  0   10  10  20                 Blackgrass                                                                           --  30  10  30  0   10  10  10  0   0   0   0   0   0                  Green foxtail                                                                        95  70  0   100 70  0   0   10  10  40  --  0   10  0                  Johnsongrass                                                                         80  10  10  10  10  0   20  0   10  10  20  10  30  0                  __________________________________________________________________________           Compound No.                                                                  43  44  45  46  47  48  49  50  51  52  53  54  55  56                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              0   20  0   20  30  90  75  60  80  90  100 95  70  90                 Wheat  0   0   0   10  75  90  85  75  80  20  80  0   20  50                 Corn   30  20  0   10  75  90  75  30  75  60  40  30  30  40                 Velvetleaf                                                                           0   80  0   100 100 100 100 100 100 100 100 100 100 100                Morningglory                                                                         0   80  --  95  100 100 100 85  100 100 100 100 100 100                Chickweed                                                                            0   80  0   100 100 100 100 100 100 100 100 100 100 100                Cocklebur                                                                            0   70  --  60  75  100 100 75  85  95  90  50  80  75                 Blackgrass                                                                           0   10  0   40  95  95  90  80  80  40  100 20  75  75                 Green foxtail                                                                        0   20  0   100 100 100 100 100 100 100 100 95  95  100                Johnsongrass                                                                         20  30  0   90  75  90  100 80  95  90  70  70  75  95                 __________________________________________________________________________           Compound No.                                                                  57  58  59  60  61  62  63  64  65  66  67  68  69  70                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              40  60  50  75  40  40  40  30  85  10  10  40  60  20                 Wheat  80  75  20  20  20  70  10  20  10  10  10  10  40  40                 Corn   75  40  20  20  20  50  10  30  10  0   10  10  20  50                 Velvetleaf                                                                           100 100 100 100 100 100 100 100 100 80  100 100 100 100                Morningglory                                                                         95  100 85  100 80  100 100 90  100 10  100 90  100 100                Chickweed                                                                            100 100 90  100 70  100 100 100 100 0   60  100 100 100                Cocklebur                                                                            70  30  75  60  10  60  75  60  80  10  30  40  90  30                 Blackgrass                                                                           80  75  70  60  40  85  70  30  50  30  60  30  40  0                  Green foxtail                                                                        100 100 90  100 100 100 100 50  100 0   75  80  100 100                Johnsongrass                                                                         80  90  80  70  70  80  75  30  80  0   10  40  95  20                 __________________________________________________________________________           Compound No.                                                                  71  72  73  74  75  76  77  78  79  80  81  82  83  84                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.25                                                                               0.25                                                                             0.3 0.25               __________________________________________________________________________    Soybean                                                                              85  40  0   10  10  20  10  10  0   0   0   0   0   10                 Wheat  20  40  0   80  60  60  5   20  10  85  0   5   5   0                  Corn   30  60  0   20  20  70  10  10  20  5   10  40  5   5                  Velvetleaf                                                                           100 100 100 100 100 100 10  100 100 100 50  95  0   0                  Morningglory                                                                         100 95  80  100 100 100 80  100 95  100 80  85  0   10                 Chickweed                                                                            100 100 100 80  75  80  20  30  95  90  15  30  90  5                  Cocklebur                                                                            85  75  20  0   10  30  10  60  0   20  20  40  0   5                  Blackgrass                                                                           0   75  70  95  75  60  5   30  40  50  60  60  0   0                  Green foxtail                                                                        100 90  100 80  100 100 20  80  70  100 95  85  --  30                 Johnsongrass                                                                         75  50  30  70  70  80  20  50  95  80  10  80  5   10                 __________________________________________________________________________

                                      TABLE 3                                     __________________________________________________________________________    POSTEMERGENCE HERBICIDAL ACTIVITY (% Control)                                        Compound No.                                                                  1   2   3   4   5   6   7   8   9   10  11  12  13  14*                       Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.25                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              60  85  95  95  80  90  95  40  100 95  80  95  70  50                 Wheat  85  100 95  100 95  100 100 20  100 100 95  100 20  50                 Corn   70  100 95  100 100 100 100 40  100 100 100 100 75  75                 Velvetleaf                                                                           100 100 100 100 100 100 100 70  100 100 100 100 80  100                Morningglory                                                                         100 100 100 100 100 100 100 100 100 100 100 100 60  100                Chickweed                                                                            90  --  100 100 100 100 100 100 100 95  100 100 0   5                  Cocklebur                                                                            50  100 100 100 100 100 100 40  100 95  100 --  60  55                 Blackgrass                                                                           30  90  95  100 40  100 100 0   100 100 95  100 5   10                 Green foxtail                                                                        100 100 100 100 100 100 100 70  100 100 100 100 20  90                 Johnsongrass                                                                         80  100 90  100 95  100 90  10  100 95  100 100 40  35                 __________________________________________________________________________     *Average of two tests  where average is not a multiple of five, given as      next lower multiple of five.                                             

    Compound No.                                                                         15  16  17  18  19  20  21  22  23  24  25  26  27  28                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.25                                                                              0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              50  75  60  85  60  70  30  70  40  90  75  60  95  95                 Wheat  95  100 30  100 100 95  20  100 15  20  10  20  15  90                 Corn   95  95  95  100 100 100 30  90  30  100 75  75  100 80                 Velvetleaf                                                                           100 100 100 100 100 100 95  100 80  100 100 60  100 90                 Morningglory                                                                         100 100 95  100 100 100 100 100 100 100 100 100 100 95                 Chickweed                                                                            10  100 20  100 100 80  20  95  40  100 100 20  100 95                 Cocklebur                                                                            60  100 80  100 100 90  80  --  20  100 100 100 100 70                 Blackgrass                                                                           5   60  10  95  100 70  20  95  5   60  0   0   10  85                 Green foxtail                                                                        100 100 30  100 100 100 95  100 15  85  80  0   90  20                 Johnsongrass                                                                         70  95  85  100 95  100 90  70  10  70  95  10  50  40                 __________________________________________________________________________           Compound No.                                                                  29  30  31  32  33  34  35  36  37  38  39  40  41  42                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              90  90  40  95  70  10  60  40  30  20  10  0   30  70                 Wheat  30  20  15  10  0   10  15  0   15  0   0   0   0   10                 Corn   80  80  100 80  50  25  25  80  10  60  10  15  30  40                 Velvetleaf                                                                           100 100 100 100 100 50  100 100 85  80  10  0   100 85                 Morningglory                                                                         100 95  100 100 100 90  100 100 50  100 0   0   100 100                Chickweed                                                                            100 95  30  100 80  0   100 95  10  80  20  0   --  70                 Cocklebur                                                                            90  100 85  --  80  10  80  95  60  --  0   0   --  90                 Blackqrass                                                                           0   10  0   0   10  0   0   0   10  0   0   0   0   0                  Green foxtail                                                                        50  80  80  60  20  0   50  30  10  30  20  0   20  30                 Johnsongrass                                                                         0   60  30  20  0   0   50  0   4   0   0   0   50  30                 __________________________________________________________________________           Compound No.                                                                  43  44  45  46  47  48  49  50  51  52  53  54  55  56                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              30  80  50  60  80  95  75  95  100 100 100 100 90  90                 Wheat  0   40  0   90  95  100 95  90  95  100 100 60  70  95                 Corn   0   70  40  75  100 100 50  90  100 100 80  70  50  60                 Velvetleaf                                                                           70  100 60  100 i00 100 100 100 100 100 100 100 100 100                Morningglory                                                                         85  100 80  100 100 100 100 100 100 100 100 100 100 100                Chickweed                                                                            0   90  0   100 100 100 100 100 100 100 100 100 95  100                Cocklebur                                                                            60  100 95  100 100 100 100 100 100 100 100 100 100 100                Blackgrass                                                                           0   0   0   80  100 100 100 100 100 85  100 60  90  95                 Green foxtail                                                                        10  20  30  100 100 100 100 100 100 100 100 100 100 100                Johnsongrass                                                                         30  10  70  100 100 100 100 100 95  100 100 100 95  100                __________________________________________________________________________           Compound No.                                                                  57  58  59  60  61  62  63  64  65  66  67  68  69  70                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                __________________________________________________________________________    Soybean                                                                              80  95  90  100 95  85  85  75  95  40  40  95  80  80                 Wheat  85  100 95  90  40  90  80  85  90  0   10  20  100 100                Corn   100 100 60  --  60  80  75  60  70  20  20  60  100 100                Velvetleaf                                                                           100 100 100 100 100 100 100 100 100 95  100 100 100 100                Morningglory                                                                         100 100 100 100 100 100 100 100 100 80  100 100 100 100                Chickweed                                                                            100 100 100 100 100 100 100 100 100 100 95  100 100 100                Cocklebur                                                                            100 95  100 100 100 100 100 100 100 100 100 100 100 100                Blackgrass                                                                           95  100 90  75  70  95  75  80  85  10  10  70  95  80                 Green foxtail                                                                        100 100 100 100 100 100 100 100 100 95  80  100 100 100                Johnsongrass                                                                         100 100 100 100 100 100 95  90  100 --  70  95  100 100                __________________________________________________________________________           Compound No.                                                                  71  72  73  74  75  76  77  78  79  80  81  82  83  84                        Rate (kg/ha)                                                           Species                                                                              0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.25                                                                              0.25                                                                              0.3  0.25              __________________________________________________________________________    Soybean                                                                              95  60  60  50  85  85  15  60  70  50  85  70  50  95                 Wheat  100 100 100 85  50  50  20  50  70  85  95  70  15  20                 Corn   100 100 100 95  80  60  50  80  100 100 100 80  70  50                 Velvetleaf                                                                           100 100 100 100 100 100 95  100 80  100 100 95  40  30                 Morningglory                                                                         100 100 100 100 100 100 100 100 100 100 100 100 40  80                 Chickweed                                                                            100 100 100 90  100 100 --  100 0   90  --  90  10  15                 Cocklebur                                                                            100 100 100 90  100 60  90  100 90  90  80  85  60  85                 Blackgrass                                                                           80  85  100 95  80  100 10  20  15  40  95  90  5   0                  Green foxtail                                                                        100 100 100 90  100 100 10  95  70  100 100 100 85  60                 Johnsongrass                                                                         100 100 95  70  95  85  20  85  85  90  85  80  40  50                 __________________________________________________________________________

I claim:
 1. A herbicidal compound of the formula ##STR26## Q is4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl; R ishydrogen, M, lower alkyl, cycloalkyl, lower alkenyl or lower alkynyl, or--[CHR⁷ (CH₂)_(m) O]_(n) R⁸,R' is hydrogen or methyl; R" is --OR oramino, phenylamino, lower alkylamino, lower alkenylamino, loweralkoxyamino, cyano, or lower alkyl-, lower haloalkyl-, orphenylsulfonylamino of the formula --N(lower alkyl)SO₂ R⁹ or --NHSO₂ R⁹; R⁷ is H or CH₃ ; R⁸ is lower alkyl; R⁹ is lower alkyl, lowerhaloalkyl, or phenyl; X is hydrogen, fluorine, or chlorine; Y ishydrogen; W is oxygen or sulfur; Z is hydrogen, fluorine, chlorine,bromine, lower alkyl, or methoxy; Z' is hydrogen, fluorine, or chlorine;m is 0 to 2, and n is 1 to 6; M is sodium, potassium or ammonium; andthe group AO-- may be in the 2, 3, or 4-position of the phenyl ring. 2.A compound of claim 1 in which R" is --OR; X is fluorine or chlorine;and Z is chlorine or lower alkyl.
 3. A compound of claim 2 in whichR islower alkyl or --[CHR⁷ (CH₂)_(m) O]_(n) R⁸ ; R' is methyl; Z is in the4-position; Z' is hydrogen or chlorine in the 3-position; m is 0 or 1,and n is 1 to 3; and the group AO-- is in the 2-position of the phenylring.
 4. A compound of claim 3 in which Q is4-difluoromethyl-4,5-dihydro-3-methyl-1,2,4-triazol-5(1H)-on-1-yl, R ismethyl or CH₃ O(CH₂)₂ --O--(CH₂)₂ --; and X is fluorine.
 5. A compoundof claim 4 in which W is oxygen and Z' is hydrogen.
 6. The compound ofclaim 5 in which R is methyl, and Z is ethyl.
 7. The compound of claim 5in which R is methyl, and Z is 2-methylethyl.
 8. The compound of claim 5in which R and Z are each methyl.
 9. The compound of claim 5 in which Ris methyl, and Z is chlorine.
 10. The compound of claim 5 in which R is2-(2-methoxyethoxy)ethyl, and Z is methyl.
 11. The compound of claim 4in which R and Z are each methyl, W is sulfur, and Z' is hydrogen.
 12. Aherbicidal composition containing a herbicidally effective amount of acompound of claim 1 in admixture with an agriculturally acceptablecarrier.
 13. A method of controlling undesired plant growth thatcomprises applying to the locus where the undesired plants are growing,or are expected to grow, a herbicidally effective amount of acomposition of claim 12.